Free Aquarium Parameter Calculator
Shrimply Tested was created out of a genuine frustration with the aquarium hobby: there was no single, free resource that combined accurate water parameter checking, species-specific guidance, practical calculators, and a record-keeping system into one tool. Most hobbyists were juggling spreadsheets, half-remembered target ranges, and forum posts from years ago — all while trying to keep sensitive, expensive shrimp alive.
This site brings everything together in one place. Whether you are a complete beginner setting up your first cherry shrimp tank, an intermediate keeper breeding Crystal Reds, or an advanced hobbyist maintaining a Taiwan Bee colony, you will find tools and information here that are immediately useful and practically actionable.
Every parameter target, every piece of guidance, every care sheet on this site has been compiled from peer-reviewed aquatic science literature, manufacturer specifications, and the accumulated practical experience of the global shrimp keeping community. We update the content regularly as new research and community knowledge emerges.
Everything on Shrimply Tested is completely free. There are no paywalls, no account requirements, and no data collection beyond what is strictly necessary for analytics. Your test results and log book entries are stored locally on your own device and are never transmitted to our servers.
Enter your test kit drop counts and instantly see if GH, KH, pH, ammonia, nitrite, and nitrate are in the safe zone for your shrimp or fish. No guesswork — just clear, colour-coded feedback tailored to your species.
Four simple steps to get instant, accurate feedback on your aquarium water — beginner-friendly!
💡 New to liquid drop testing? See the step-by-step testing procedures section below for guidance before you start.
Water chemistry is the single most important factor in the health, survival, and breeding success of aquarium shrimp and fish. Unlike terrestrial animals that can tolerate significant changes in their environment, aquatic creatures live entirely within their water column — every molecule they breathe, every mineral they absorb, every pH fluctuation they experience has a direct impact on their physiology.
For sensitive species like Crystal Red Shrimp and Taiwan Bee Shrimp, even a 0.2 swing in pH or a 1-drop increase in KH can be enough to stress the animals into failed molts, dropped eggs, or death within hours. For hardier species like Cherry Shrimp, the tolerance window is wider — but the same principles apply. Understanding exactly where your parameters sit relative to your animals' requirements is the foundation of successful aquarium keeping.
This calculator was built to make that process as simple and accurate as possible. Rather than trying to memorise target ranges for multiple species, cross-reference drop counts with PPM charts, and mentally assess whether each parameter is acceptable, you enter your numbers and get an instant, comprehensive analysis. It handles the chemistry so you can focus on enjoying your tank.
There are three common ways hobbyists test their aquarium water: paper test strips, liquid drop test kits, and digital meters. Each has its place, but they are not equally reliable.
Paper test strips are the least accurate option. The colour-reactive pads are sensitive to humidity and finger oils, the colour chart comparisons are subjective, and different parameters can bleed into each other. They are useful for a quick sanity check but should never be relied upon for sensitive species.
Liquid drop test kits — like the API Master Test Kit that this calculator is calibrated around — use precise chemical reactions. You add drops of reagent until the water changes colour, then count the drops. Each drop equals exactly one degree of hardness (for GH and KH), making the conversion to PPM mathematically reliable. These kits provide lab-grade accuracy at a hobbyist price point.
Digital meters (TDS meters, pH pens, refractometers) are fast and convenient for on-the-spot readings, but they require regular calibration and cannot distinguish between different dissolved compounds. A TDS meter, for example, cannot tell you whether your dissolved solids are beneficial minerals or harmful nitrates. Use digital meters as a supplement to liquid tests, not a replacement.
↑ To Raise: Add liquid/powder remineralizer (e.g., SaltyShrimp GH+), crushed coral, or Wonder Shells.
↓ To Lower: Dilute minerals by performing water changes with pure RO/DI or Distilled water.
↑ To Raise: Add commercial alkaline buffers (KH+), crushed coral, or baking soda (dose carefully).
↓ To Lower: Use RO/DI water. Note: Active buffering soils naturally strip KH to 0.
↑ To Raise: Increase surface agitation (air stone) to gas off CO2, or add crushed coral/limestone.
↓ To Lower: Add botanical tannins (Indian Almond Leaves, Alder Cones, Driftwood) or Peat moss.
⚠️ If Above Zero: Highly toxic. Perform an immediate 30-50% water change. Dose a detoxifier like Seachem Prime immediately.
↓ To Lower: Nitrates are the end-product of the cycle. Remove them via routine 20% water changes. Add fast-growing floating plants (Frogbit, Salvinia, Hornwort).
Enter test drops/ppm in the panels above.
A complete plain-English guide to what each parameter actually means, why it matters, and what happens when it goes wrong.
General Hardness measures the concentration of dissolved calcium (Ca²⁺) and magnesium (Mg²⁺) ions in your water. These two minerals are the most biologically critical for invertebrates and fish alike. For shrimp, calcium is the primary structural mineral in their exoskeleton. Without adequate GH, a shrimp attempting to molt — a process they must complete every few weeks — cannot form a new shell hard enough to support their body weight. The result is a failed molt, leaving the shrimp trapped in its old shell and slowly dying.
Magnesium plays a supporting role in enzyme function, nerve transmission, and muscle contraction. Deficiencies show as lethargy, erratic swimming, and reproductive failure. For fish, GH affects the rate of ion exchange across the gill membrane — fish in water that is too soft or too hard must expend significantly more energy on osmoregulation, leaving less energy for growth, immunity, and reproduction.
GH cannot be reduced chemically. The only way to lower GH is by diluting tank water with RO/DI or distilled water. To raise GH, add a hardness mineral such as SaltyShrimp GH+ or Seachem Equilibrium.
Carbonate Hardness (KH) measures the concentration of carbonate (CO₃²⁻) and bicarbonate (HCO₃⁻) ions in the water. These act as a chemical buffer, neutralising both acids and bases to keep pH from swinging dramatically. This buffering capacity is arguably the most underappreciated concept in freshwater fishkeeping.
A tank with a KH of 0 has no buffering capacity. In such a tank, the natural production of CO₂ by respiring animals and bacteria will cause pH to drop steadily overnight. In a heavily planted tank, pH can swing by 1.0 or more units between lights-on and lights-off — a swing that is acutely stressful to most fish and lethal to many invertebrates. Even a KH of 1–2 drops provides meaningful buffering in a small tank.
For Caridina shrimp that require soft, acidic water, KH is intentionally kept at or near 0 — with pH stability managed instead by active buffering soil substrates. For all other freshwater applications, maintaining KH above 3 drops is strongly recommended. KH can be raised with sodium bicarbonate (baking soda) or a dedicated KH buffer product.
pH measures the concentration of hydrogen ions in solution, expressed on a logarithmic scale from 0 (extremely acidic) to 14 (extremely alkaline), with 7.0 being neutral. Because the scale is logarithmic, a pH of 6.0 is ten times more acidic than a pH of 7.0, and a pH of 5.0 is one hundred times more acidic. This is why small pH changes that look insignificant on paper can have significant biological effects.
pH affects every chemical process in the tank. At lower pH, ammonia (NH₄⁺) remains in its less toxic ionised form. At higher pH, it converts to the highly toxic free ammonia (NH₃) form — meaning the same ammonia reading is far more dangerous in an alkaline tank than an acidic one. pH also affects the efficiency of beneficial bacteria in the nitrogen cycle, the availability of minerals, and the permeability of gill tissue.
Most freshwater community fish thrive in a pH range of 6.5–7.5. Always test pH at the same time of day for consistent comparisons — photosynthesis during the day raises pH, while CO₂ production at night lowers it. A reliable KH level keeps these swings manageable.
Ammonia is the primary waste product excreted by fish and invertebrates through their gills and is also produced by the decomposition of any organic matter — uneaten food, dead plant material, dead animals. In a fully cycled aquarium, beneficial bacteria (Nitrosomonas species) convert ammonia to nitrite almost as fast as it is produced, keeping readings at 0 ppm. In a new, uncycled tank, ammonia accumulates rapidly and can reach lethal levels within 24–48 hours of adding livestock.
Total ammonia exists in two forms: ionised ammonium (NH₄⁺), which is relatively harmless, and un-ionised free ammonia (NH₃), which is acutely toxic. The ratio between the two forms is determined by pH and temperature — higher pH and higher temperature push the equilibrium toward the toxic NH₃ form. Even 0.02 ppm of free NH₃ is sufficient to cause gill damage in sensitive fish. At 0.5 ppm free NH₃, death can occur within hours.
Any ammonia reading above 0 ppm is an emergency. Immediately perform a 30–50% water change, dose with Seachem Prime (which detoxifies ammonia for 48 hours), stop all feeding, and identify the source of the ammonia spike. Retest every 24 hours until readings return to 0.
Nitrite is the intermediate compound in the nitrogen cycle, produced when Nitrosomonas bacteria oxidise ammonia. It is then converted to the far less toxic nitrate by a second group of bacteria (Nitrospira species). In a fully mature aquarium, nitrite should always read 0 ppm. Elevated nitrite readings indicate either an incomplete cycle (common in new tanks) or a disruption to the bacterial colony — caused by chlorinated water changes, antibiotics, overfeeding, or a sudden increase in bioload.
Nitrite toxicity works through a mechanism called methemoglobinemia. Nitrite ions (NO₂⁻) enter the bloodstream across the gill membrane and convert haemoglobin (which carries oxygen) to methaemoglobin (which cannot carry oxygen). The animal effectively suffocates in oxygenated water. Fish with nitrite poisoning gasp at the surface, show rapid gill movement, and display a brownish discolouration of the gills. Shrimp become lethargic and may swim erratically.
Nitrite is particularly toxic to shrimp and scaleless fish. Any reading above 0 ppm requires immediate action: water change, Seachem Prime, stop feeding, increase aeration. Aquarium salt (sodium chloride) at 1 tablespoon per 10 gallons can help fish tolerate short-term nitrite exposure, but should not be used long-term in shrimp tanks.
Nitrate is the end product of the nitrogen cycle and the form of nitrogen that accumulates in closed aquarium systems over time. Unlike ammonia and nitrite, nitrate is not acutely toxic at low concentrations — most fish can tolerate levels up to 40–80 ppm without visible distress. However, chronically elevated nitrate has significant long-term health consequences, including suppressed immune function, stunted growth, reduced reproductive success, and increased susceptibility to disease.
For shrimp — particularly Caridina species — nitrate tolerance is much lower. Crystal Red and Taiwan Bee Shrimp show stress responses at nitrate levels above 10–15 ppm, and breeding virtually stops above 20 ppm. Sulawesi Cardinal Shrimp are even more sensitive. High nitrate combined with slightly elevated ammonia (below the detectable threshold of most test kits) is one of the most common causes of unexplained shrimp deaths in otherwise well-maintained tanks.
The primary mechanism for nitrate control is regular partial water changes. Live plants — particularly fast-growing stem plants, floating plants, and moss — consume nitrate as a fertiliser and can significantly slow its accumulation. In heavily planted tanks, nitrate can remain near 0 indefinitely without water changes. Aim to keep nitrate below 20 ppm for community fish and below 10 ppm for sensitive shrimp species.
Prevents wide pH swings in the aquarium.
Measures Calcium & Magnesium levels.
Critical for detecting toxic ammonia spikes.
If you have difficulty discerning the color after the first drop: remove the cap, hold the tube over a white background, and look down through the tube.
Reminder:
Each drop is equal to 1 degree of hardness (dGH/dKH).
Track every test, spot parameter drift before it becomes a crisis, and download your records as a PDF.
A single test result tells you what your water is right now. A log of 20 tests tells you the story of your tank — whether parameters are creeping in the wrong direction, whether your remineralizer is running low, whether your substrate is exhausting its buffering capacity. Patterns that are invisible in a single reading become obvious trends over time. Most experienced shrimp keepers describe the moment they started logging as the turning point where their success rate dramatically improved.
The chart plots your last 20 test results over time. GH, KH, and NO3 share the left axis (drops/ppm), while pH uses the right axis to keep its narrower range readable. Look for gradual trends rather than single spikes — a slow rise in NO3 week over week signals that your water change frequency needs to increase. A slow fall in KH in a Neocaridina tank suggests your tap water's buffering capacity has changed, which is common seasonally as water utilities adjust treatment.
The Log PDF export generates a formatted table of your complete testing history, suitable for printing or sharing with a veterinarian or experienced keeper. The Care Sheet PDF combines your species' target parameters with your recent test history and an emergency action protocol — a single document that tells anyone caring for your tank exactly what they need to know. The blank Template PDF is useful for paper-based tracking when testing away from a computer.
Save at least 2 test results to see trends. Showing last 20 entries.
| Date | Target | Tank Size | GH | KH | pH | NH3 | NO2 | NO3 | Status |
|---|
Compare ideal water conditions across all species side by side. All GH/KH values use API liquid drop test kit measurements. 1 drop = 17.86 ppm.
Every value in this reference chart corresponds directly to what you would read from an API GH & KH liquid drop test kit — the most widely used standard in the hobby. The "drops" column tells you exactly how many drops your test should require before the colour changes. The ppm equivalent is calculated at the standard conversion rate of 17.86 ppm per drop.
The pH ranges listed represent the stable operating range for each species — not the extremes they can briefly survive. Parameters at the edge of a range are always less ideal than parameters in the centre. A Cherry Shrimp at pH 7.8 is technically within range but will breed less prolifically and live shorter than one maintained at pH 7.2. Always aim for the middle of the target range, not the edges.
Temperature is not listed as a parameter in the main calculator because it is managed by equipment rather than water chemistry, but it significantly affects the biological impact of every other parameter. Higher temperatures increase metabolism, oxygen demand, the toxicity of ammonia, and the rate of bacterial activity. Cooler temperatures extend lifespan in most shrimp species and improve colour intensity.
| Species / Target | GH (Drops / PPM) | KH (Drops / PPM) | Ideal pH | Max Nitrate (NO3) |
|---|---|---|---|---|
| 🦐 Shrimp Colonies | ||||
| Cherry / Neocaridina |
6 - 10 Drops 107 - 179 PPM |
2 - 5 Drops 36 - 89 PPM |
6.8 - 7.8 | < 20 ppm |
| Crystal Red (Caridina) |
4 - 6 Drops 71 - 107 PPM |
0 - 1 Drops 0 - 18 PPM |
6.2 - 6.8 | < 10 ppm |
| Taiwan Bee |
4 - 5 Drops 71 - 89 PPM |
0 Drops 0 PPM |
5.8 - 6.4 | < 10 ppm |
| Ghost Shrimp |
5 - 8 Drops 89 - 143 PPM |
5 - 8 Drops 89 - 143 PPM |
7.0 - 8.0 | < 20 ppm |
| Sulawesi Cardinal |
6 - 8 Drops 107 - 143 PPM |
4 - 8 Drops 71 - 143 PPM |
7.8 - 8.5 | < 10 ppm |
| 🐟 API General Fish Guidelines | ||||
| Soft Water (Discus, Neons) |
0 - 3 Drops 0 - 54 PPM |
0 - 3 Drops 0 - 54 PPM |
6.0 - 7.0 | < 40 ppm |
| Community (Tetras, Angelfish) |
3 - 6 Drops 54 - 107 PPM |
3 - 6 Drops 54 - 107 PPM |
6.5 - 7.5 | < 40 ppm |
| Hard Water (Guppies, Mollies) |
6 - 11 Drops 107 - 196 PPM |
6 - 11 Drops 107 - 196 PPM |
7.0 - 8.0 | < 40 ppm |
| Very Hard (African Cichlids) |
11 - 22 Drops 196 - 393 PPM |
11 - 22 Drops 196 - 393 PPM |
7.8 - 8.5 | < 40 ppm |
Everything you need to know about keeping and breeding each species — click any card to expand.
Ideal for: Beginners, community tanks, heavily planted setups. One of the hardiest ornamental shrimp available.
Temperature: 65–80°F (18–27°C). Cooler temps mean longer lifespan; warmer temps mean faster breeding but shorter lives.
Tank size: Minimum 5 gallons. A 10-gallon dedicated colony tank is ideal — you'll have dozens within months.
Breeding: Females saddle up (visible yellow/green egg mass behind head) then transfer eggs to berry (holds 20-40 eggs). Eggs hatch fully-formed tiny shrimp after ~28 days at 72°F. No larval stage — babies are immediately self-sufficient.
Diet: Biofilm grazer — they'll eat algae, decaying leaves, and anything that falls to the bottom. Supplement with blanched vegetables (zucchini, spinach), specialized shrimp pellets, and occasional protein (frozen bloodworm, baby brine shrimp).
Tankmates: Avoid any fish that fits a shrimp in its mouth. Safe with small tetras, rasboras, otocinclus, corydoras. Never with bettas, gouramis, or cichlids.
Color grades: Red Cherry (lowest), Sakura, Fire Red, Painted Fire Red (highest grade, deepest red). Color is hereditary — cull lightly colored shrimp to improve colony color over time.
Requires: RO/DI water remineralised with Caridina-specific mineral (SaltyShrimp GH+). Active buffering soil (ADA Aquasoil, Fluval Stratum) is mandatory for pH stability.
Temperature: 62–72°F (17–22°C). Lower temps are preferred — they are cool water shrimp from mountain streams. A chiller is beneficial in summer.
Grading system: Graded S–SSS based on pattern clarity. SSS grade has solid, crisp red/white bands with no bleeding. Higher grade = higher price and more sensitive.
Breeding: Slower than Neocaridina — females berry less frequently. Clutch of 15-25 eggs, 28-32 day incubation. Parameters must remain rock-solid or females abort eggs.
Common mistakes: Tap water (any KH will fight the soil), sudden temperature changes, inconsistent water changes, overfeeding (NO3 spikes are lethal).
Tankmates: Species-only tank strongly recommended. Even "peaceful" fish will eat juvenile shrimp. Can be kept with other Caridina species.
Background: Created by crossing Crystal Red shrimp with wild Caridina shrimp. Varieties include King Kong, Panda, Blue Bolt, Shadow Panda, and Fishbone — all command premium prices ($20–$200+ per shrimp).
Water requirements: The most demanding freshwater shrimp available. KH must be strictly 0. pH 5.8–6.2 is the sweet spot for breeding. Achievable only with RO/DI + active soil + zero tap water involvement.
Temperature: 60–70°F (15–21°C). A dedicated aquarium chiller is virtually mandatory in most climates. Temperature spikes above 75°F can kill the entire colony within hours.
Feeding: Very light feeding — 2-3 times per week maximum. High organic load crashes parameters. Biofilm from established tanks is their primary food source.
Not recommended for: Anyone without prior experience keeping Crystal Reds successfully for 12+ months.
Overview: Nearly transparent, ultra-hardy, and widely available. Often sold as feeder shrimp but make excellent, active tank cleaners in their own right.
Breeding challenge: Larvae are free-swimming and require brackish water to survive — unlike Neocaridina, juveniles cannot survive in freshwater. This makes breeding in a standard freshwater setup nearly impossible without dedicated brackish nursery setup.
Temperature: 65–80°F (18–27°C) — very adaptable.
Uses: Excellent tank cleaners, algae eaters, and live food for larger fish. Can coexist with most peaceful community fish due to their size and speed.
Unique requirements: Unlike all other shrimp on this page, Sulawesi Cardinals require warm, alkaline water — the opposite of Caridina. They come from ancient, isolated lakes in Sulawesi, Indonesia with very specific mineral compositions.
Temperature: 78–88°F (26–31°C). A heater is mandatory. They will not survive temperatures below 75°F.
Water source: Most keepers use RO/DI water remineralised with Sulawesi-specific mineral salts (SaltyShrimp Sulawesi 8+) to replicate the lake's unique chemistry. Tap water is rarely suitable.
Conservation: Many Sulawesi shrimp species are critically endangered in the wild due to habitat destruction. Captive breeding is actively encouraged.
Price: Rare and expensive ($10–$50+ each). Handle carefully and never expose to temperature or parameter swings.
Save a custom species profile with your own target parameter ranges.
Curated by the Shrimply Tested community — the tools and products we actually use and recommend.
Links may be affiliate links. This helps keep the site free at no extra cost to you.
Every product listed on this page has been selected based on one criterion: does it actually work? We do not accept payment for product placements and do not recommend products we would not use ourselves. Our recommendations are based on a combination of direct testing, community feedback collected over time, and consistency of results reported across hundreds of tanks in multiple countries.
Aquarium product marketing is notoriously unreliable — labels make claims that the science does not support, and budget products are sometimes just as effective as expensive ones. Where a cheaper alternative is equally good, we recommend it. Where a premium product genuinely outperforms cheaper options, we explain exactly why. Our goal is to help you spend your money wisely and get the best results for your animals.
The industry standard. Tests NH3, NO2, NO3, and pH with 800+ tests per kit. Accurate, affordable, and what this calculator is designed around.
Best Value · ~$35Separate kit specifically for hardness testing. Essential for shrimp keepers. Sold separately from the master kit.
Essential for Shrimp · ~$10Lab-grade accuracy for individual parameters. Worth it for experienced breeders who want the most precise readings possible.
Pro Grade · ~$15 eachThe best dechlorinator available. Also temporarily detoxifies ammonia and nitrite. Use for every water change.
Must-Have · ~$12Premier remineralizer for Neocaridina tanks. Balanced calcium, magnesium, and carbonates. Consistent results every time.
Neocaridina · ~$18KH-free remineralizer for Caridina tanks using active buffering soil. Raises GH without introducing carbonates.
Caridina · ~$18Bottled beneficial bacteria to cycle new tanks or recover from mini-cycles. Dose daily for 2 weeks in new tanks.
Cycling · ~$12The best filter for shrimp tanks. Gentle flow, no risk of sucking up babies, and excellent biological filtration surface area.
Shrimp Safe · ~$10Instant total dissolved solids reading in seconds. Essential for RO/DI water quality checks and overall water monitoring.
Must-Have · ~$15The gold-standard active buffering soil for Caridina tanks. Reliably lowers and holds pH in the 6.0–6.8 range for 12–18 months.
Caridina Substrate · ~$35Natural tannin source that gently lowers pH, releases antibacterial compounds, and provides biofilm surfaces shrimp love grazing on.
Natural pH · ~$8 / 50 leavesThe most important thing any new aquarium owner must do — and the most commonly skipped. This step-by-step guide will get your tank ready for shrimp or fish safely.
Every year, millions of fish and shrimp die from "New Tank Syndrome" — the result of putting animals into an uncycled tank. Ammonia builds up within 24 hours, becomes lethal within days, and without beneficial bacteria to process it, the entire tank crashes. Cycling is non-negotiable. It takes 4–8 weeks, but the tank will be stable and safe for years afterward.
Add substrate, filter, heater, and decorations. Fill with dechlorinated water. Set temperature to 78–82°F to encourage faster bacterial growth. Do NOT add livestock yet.
Days 1–2
Add pure ammonia (Dr. Tim's or pure unscented ammonia) to reach 2–4 ppm. Alternatively use fish food that will rot. This feeds the bacteria you're growing. Add bottled bacteria (Seachem Stability) daily.
Days 2–7
Test every 2–3 days. Ammonia will rise then fall as Nitrosomonas bacteria establish. Nitrite will appear and spike as those bacteria overwhelm Nitrospira capacity. Keep adding ammonia if it drops to 0.
Weeks 2–5
The tank is fully cycled when: ammonia reads 0, nitrite reads 0, and nitrate is rising. Confirm by adding a dose of ammonia — it should reach 0 within 24 hours. Do a large water change and add your livestock!
Week 4–8
If you already have fish/shrimp in an uncycled tank, act immediately:
The nitrogen cycle is a biological process driven by two distinct groups of chemoautotrophic bacteria — organisms that derive energy from chemical reactions rather than sunlight. The first group, dominated by Nitrosomonas species, oxidises ammonia (NH₃) into nitrite (NO₂⁻) as their energy source. The second group, dominated by Nitrospira species, oxidises nitrite into nitrate (NO₃⁻). Together they form a two-stage biological filter that converts the most toxic compound in your tank into the least toxic one.
These bacteria are strict aerobes — they require dissolved oxygen to function. This is why maximising aeration during the cycling process is critical. They also reproduce slowly compared to most bacteria, with a doubling time of 8–24 hours, which is why cycling takes weeks rather than days. They colonise porous surfaces — filter media, substrate particles, decoration surfaces — rather than living freely in the water column. This is why you should never clean your filter with tap water: chlorine kills the bacteria you have spent weeks cultivating.
Temperature dramatically affects bacterial growth rate. At 77–82°F (25–28°C), the cycle runs at maximum speed. At 68°F (20°C), bacterial metabolism slows significantly. At 60°F (15°C) or below, cycling can take twice as long. If you are cycling a shrimp tank that will ultimately be kept cool, you can cycle at a higher temperature and then gradually lower it once the cycle is established.
A cycled tank is not permanently cycled — the bacterial colony must be maintained. Anything that kills or removes a significant portion of the bacteria will cause a "mini-cycle" where ammonia and nitrite temporarily spike again. Common causes include: cleaning filter media in tap water, adding medications (especially antibiotics and many anti-parasite treatments), extended power outages (bacteria die within 4–8 hours without oxygenated flow), very large water changes with cold chlorinated water, and completely replacing substrate.
If you need to medicate your tank, either remove your filter media to a bucket of tank water with an airstone while medicating, or dose the tank with a bacterial product after the treatment course ends. Always dechlorinate replacement water before it contacts your filter. If you suspect a mini-cycle, test daily and treat as you would any ammonia/nitrite spike.
The most important long-term maintenance habit is regular, consistent water changes. Beyond removing nitrate, water changes replenish trace minerals, remove dissolved organic compounds that accumulate invisibly, and reset the carbonate buffering capacity. In a mature, stable aquarium, a 20–30% weekly water change prevents most water quality problems before they start — it is cheaper, easier, and more effective than any chemical treatment or additive on the market.
Most aquarium failures follow predictable patterns. Understanding these mistakes before you make them is the fastest path to a thriving tank.
This is far and away the most common cause of death in new aquariums. An uncycled tank has no beneficial bacteria to process waste, so ammonia accumulates from the moment you add livestock. Fish and shrimp can survive days in this environment, giving false reassurance, before the ammonia reaches lethal levels. The solution is simple: cycle your tank first (see the guide above) and never add livestock to an aquarium that hasn't completed the nitrogen cycle.
If you've already made this mistake and animals are in an uncycled tank, perform daily water changes of 30–50% using dechlorinated water, dose Seachem Prime every 48 hours, stop feeding, and add bottled bacteria daily until readings stabilise at 0/0 for ammonia and nitrite.
The classic "inch per gallon" rule is outdated and misleading. A tank's carrying capacity depends on filtration capacity, surface area for gas exchange, and the bioload of the specific animals — not just tank volume. In shrimp keeping, overstocking is rarely a problem because shrimp produce very little waste relative to their size, but in fish tanks it is endemic. Overstocked tanks require more frequent water changes, are more prone to disease outbreaks, and produce more stress hormones (which suppress immunity) even when water quality appears acceptable.
A better rule of thumb: stock slowly and let your test kit tell you when you've reached capacity. If nitrate is rising faster than your water change schedule can control it, you're overstocked or underfiltered.
Many hobbyists, concerned about algae or detritus, perform a full deep clean — scrubbing the glass, rinsing all decorations, vacuuming the entire substrate, and cleaning the filter — all in the same session. This is one of the most reliable ways to crash a cycled tank. The beneficial bacteria live on all these surfaces. Remove them all at once and you effectively recycle your tank from scratch.
Stagger your maintenance: clean the glass one week, vacuum part of the substrate the next, and never clean filter media and substrate in the same session. Filter media should only be rinsed in old tank water (removed during a water change), never under the tap.
Crystal Red, Crystal Black, Taiwan Bee, and other Caridina shrimp require soft, acidic water with a KH of zero. Most tap water in developed countries has a KH of 3–8 drops — which will actively fight the active substrate that Caridina tanks depend on, exhaust the substrate prematurely, cause dangerous pH instability, and stress the animals. Even if your tap water appears to have acceptable parameters, seasonal variations in municipal water treatment can cause sudden changes that crash a Caridina tank overnight.
The only reliable approach for Caridina species is RO/DI water remineralised with a KH-free mineral product. An entry-level RO unit pays for itself in substrate savings within the first year.
Uneaten food is the primary driver of ammonia spikes in established tanks. Fish and shrimp should be fed only what they can consume within 2–3 minutes, once or twice daily. Any food remaining after that should be removed. Shrimp in particular require very little supplemental feeding in a tank with established algae and biofilm growth — many experienced keepers feed their shrimp colonies only 2–3 times per week and achieve better results than those who feed daily.
Signs of overfeeding: cloudy water, algae blooms, rising nitrate between water changes, a film on the water surface, and detritus accumulating faster than you can remove it. If you are seeing any of these, reduce feeding immediately and check your parameters.
Aquarium keeping forums are full of advice to hit precise parameter targets, and while accuracy matters, the pursuit of perfection can itself cause harm. Animals adapt to stable conditions over time — a cherry shrimp colony at pH 7.4 is not suffering just because the "ideal" is 7.2. What kills fish and shrimp is not imperfect parameters but rapid change. A tank at pH 7.6 is healthier than a tank swinging between 6.8 and 7.8 every 24 hours.
Focus on stability first. Once your tank has been stable for 2–4 weeks, make small, gradual adjustments toward the target range if needed. Never try to correct parameters in a single large intervention — change 10–15% at a time and retest before proceeding further.
Moving a fish or shrimp from the store bag to your tank without acclimation is a significant osmotic shock. Store water and tank water are rarely identical, and the sudden change in parameters — even if both are within acceptable ranges — can stress and kill sensitive animals. For fish, float the bag for 15–20 minutes to equalise temperature, then add small amounts of tank water to the bag over 30–45 minutes before transferring.
For shrimp, the drip acclimation method is strongly recommended: place the shrimp in a container with their store water, set up a drip line from your tank, and allow tank water to drip in at 1–2 drops per second for 1–2 hours before transferring. Never add store water to your tank — it may contain pathogens or unwanted hitchhikers.
When fish become ill, the instinct is to treat with medication. But applying the wrong medication stresses already weakened fish, kills beneficial bacteria, and in many cases does nothing to address the actual problem — which is often water quality, not disease. Before reaching for any medication, test your water comprehensively and rule out parameter issues as the cause of the symptoms.
Many of the most common symptoms attributed to disease — clamped fins, lethargy, rapid breathing, loss of colour, staying near the surface — are actually responses to poor water quality. A 30–50% water change with dechlorinated water is the correct first response in virtually every situation and will either solve the problem directly or at least rule out water quality as a cause.
Shrimp are prey animals. Almost any fish species that can physically fit a shrimp in its mouth will eventually eat it, including species that are widely marketed as "shrimp safe." Bettas, gouramis, angelfish, cichlids, larger tetras, and most loaches pose serious risks to shrimp colonies. Even fish that do not actively hunt shrimp will often pick off newly molted individuals whose soft shells make them vulnerable for 12–24 hours after molting.
The safest shrimp tankmates are small, surface-dwelling fish that never venture to the bottom: ember tetras, chili rasboras, small celestial pearl danios, and otocinclus catfish. When in doubt, run a species-only shrimp tank — a healthy, breeding colony of cherry shrimp is genuinely one of the most visually rewarding displays in freshwater fishkeeping.
This sounds obvious, but the single most common thread in every aquarium disaster story on every forum is: "I hadn't tested in a while." Water quality deteriorates gradually and invisibly. A tank can look crystal clear, with active, apparently healthy animals, while ammonia quietly climbs to dangerous levels over two weeks of overfeeding and skipped water changes.
Establish a testing routine. For new tanks and new species, test every 2–3 days. For mature, stable tanks, weekly testing is the minimum. Use the log book and reminder features on this site to build the habit. Your test kit is the most important tool in your fishkeeping toolkit — more important than any filter, any additive, or any piece of equipment you will ever buy.
The most important maintenance task in fishkeeping — done right, it prevents virtually every water quality problem. Done wrong, it causes them.
A partial water change achieves several things simultaneously that no chemical treatment, filter, or additive can replicate. It dilutes accumulated nitrate, the end product of the nitrogen cycle that builds up regardless of filtration quality. It replenishes minerals that are gradually consumed by plants, absorbed by animals, and lost to evaporation-driven concentration. It removes dissolved organic compounds — the invisible soup of tannins, proteins, and metabolic byproducts that builds up over time and creates the "old tank smell." And it partially resets the carbonate buffering capacity of the water, helping maintain stable pH.
No product on the market can replicate what a regular water change achieves. Products that claim to "eliminate water changes" are not removing waste — they are converting it into forms that the test kit cannot detect, or stimulating plant growth to consume nitrates. They may temporarily mask symptoms, but without regular water changes, dissolved organic load continues to build and will eventually impact animal health.
The general guideline for a moderately stocked, filtered community tank is 20–30% weekly. For heavily stocked tanks or those with large messy fish (cichlids, goldfish, plecos), 30–40% twice weekly is appropriate. For shrimp-only tanks with low bioload and planted tanks where plants are consuming nitrate, 10–15% weekly or 20–25% every two weeks is often sufficient.
The right frequency is ultimately determined by your test results: if nitrate is still below 20 ppm the day before your scheduled water change, your current schedule is adequate. If nitrate regularly reaches 30–40 ppm, increase frequency. Use the Water Change Calculator above to determine the exact volume needed to bring nitrate to your target level.
Shrimp are more sensitive to the disturbance and parameter shifts of water changes than most fish. Use a thin siphon tube or airline tubing instead of a gravel vacuum when removing water, to avoid sucking up shrimp hiding in the substrate. Remove water slowly rather than all at once — taking 5–10 minutes to remove 20% is far less stressful than doing it in 30 seconds.
Add replacement water slowly. Pouring water directly into the tank disturbs the substrate and can cause sudden cold or parameter shocks. Use a clean bucket and pour over a plate or decoration to diffuse the flow, or drip water in using a tube with a valve. Always ensure replacement water is within 2°F of tank temperature and has been dechlorinated before adding.
For Neocaridina and fish tanks using tap water: fill a bucket 24 hours in advance, add dechlorinator (Seachem Prime at 1 drop per litre), and allow to stand at room temperature overnight. This allows chloramine to dissipate and temperature to equalise. For tanks with heaters, you can alternatively dechlorinate and use immediately, ensuring the temperature is matched.
For Caridina tanks using RO/DI water: mix remineralizer into the RO water in a separate container, test the GH, and allow to reach tank temperature before adding. Never add RO water directly to a Caridina tank without remineralizing it first — pure RO water has a GH and TDS of near zero, which is acutely hypotonic and will stress shrimp.
For tanks with live plants, avoid adding water conditioners directly to the tank when possible — many dechlorinators temporarily reduce dissolved oxygen and can stress plants. Pre-treat water in a separate container instead.
Consistency is more important than perfection. A tank that receives a reliable 20% change every Sunday is in better condition than a tank receiving sporadic 40% changes whenever the owner remembers. Animals adapt to the rhythm of regular water changes — experienced keepers often report that their shrimp become notably more active and feeding-responsive immediately after a water change, recognising the stimulus as a trigger that rainfall-equivalent events bring in the wild.
Use the test reminder feature on this site to schedule both testing and water change reminders simultaneously. If you test every 3 days and do a water change every 7 days, set two separate reminders. The combination of regular testing and regular water changes is the single most reliable formula for long-term aquarium success.
The Water Change Calculator in the Tools section above will tell you exactly how many gallons to change based on your current and target GH and NO3 levels, accounting for the parameters of your replacement water. Stop guessing — calculate first, then act.
Diagnose the most common aquarium problems from symptoms. Always test your water first — most issues trace back to parameters.
Most likely causes: (1) TDS is too high — even if GH, KH, and pH look correct, accumulated dissolved solids can stress shrimp. Test TDS with a TDS meter. (2) Copper contamination — new pipes, some fertilisers, and many medications contain copper which is acutely toxic to invertebrates at extremely low levels. (3) The "parameters look fine" issue — test kits have a detection threshold. Ammonia at 0.25 ppm may read as 0 on a colour chart. Test with a more sensitive method. (4) Failed molt — check for shrimp stuck in their old shell. This indicates GH is too low or the molt was triggered too rapidly by a parameter change.
Action: Test TDS, check for copper sources, perform a 30% water change, and examine any dead shrimp for signs of failed molt. Review your recent change log for anything unusual added to the tank.
Most likely causes: Low dissolved oxygen (the most common cause), ammonia toxicity, nitrite toxicity, or gill damage from poor water quality. Fish gasping at the surface specifically (as opposed to swimming erratically at all levels) almost always indicates oxygen deprivation. This can result from high temperature reducing oxygen solubility, a power outage stopping surface agitation, or a sudden algae die-off consuming oxygen overnight.
Immediate action: Add aeration urgently (even pointing a powerhead at the surface helps). Perform a 30–50% water change. Test ammonia and nitrite — if either reads above 0, dose with Seachem Prime and continue water changes. Do not feed until the situation is resolved. Check your filter is running and creating surface movement.
Cause: KH is too low, leaving the water without adequate buffering capacity. CO₂ produced by respiring animals, bacteria, and plants at night acidifies the water, and with insufficient carbonate ions to neutralise it, pH drops. In planted tanks with CO₂ injection, this effect is amplified. Test KH — if it reads 0–1 drops, this is almost certainly your problem.
Solution: Raise KH gradually using sodium bicarbonate (1/4 teaspoon per 10 gallons raises KH by approximately 1 drop) or a dedicated KH buffer product. Add it to replacement water during water changes rather than directly to the tank, to avoid rapid pH shifts. For planted Caridina tanks that deliberately maintain KH at 0, use a high-quality active substrate and ensure adequate surface agitation to off-gas CO₂.
Common causes: (1) All one gender — check if you have both males and females. Males are smaller, slimmer, and more active. Females have a visible saddle (yellow/green egg mass) behind the head when ready to breed. (2) Tank is too new — shrimp won't breed in an unstable environment. A tank needs to be stable for at least 4–6 weeks before most species will begin breeding. (3) Nitrate too high — even technically safe nitrate levels above 15–20 ppm suppress breeding in Caridina species. (4) Temperature out of optimal range — slightly cooler water (within the acceptable range) often triggers breeding behaviour more effectively than warmer water.
Action: Verify you have multiple females (look for saddled females). Confirm all parameters are stable and nitrate is below 15 ppm. Consider a small (10%) water change with slightly cooler water — temperature variation often triggers breeding. Ensure the tank has been established for at least 6 weeks.
Cause: Algae thrives when light, nutrients (especially nitrate and phosphate), and CO₂ are out of balance. In most cases, the primary driver is excessive light duration or intensity combined with elevated nutrients. Most aquarium lights should run for no more than 8 hours per day. More light is not better — plants use what they need and excess light feeds algae.
Solutions: Reduce photoperiod to 6–8 hours. Increase plant density (fast-growing stem plants compete directly with algae for nutrients). Add algae-eating livestock: nerite snails are the most effective algae cleaners for shrimp tanks and will not harm shrimp or eggs. Otocinclus catfish are excellent for soft algae films on glass and plants. Reduce feeding to lower phosphate input. Address any elevated nitrate with a water change schedule. Manual removal combined with addressing the root cause is far more effective than chemical algaecides, which can harm livestock and beneficial bacteria.
Cause: White or milky cloudiness in an established tank is almost always a bacterial bloom — a sudden population explosion of free-floating heterotrophic bacteria, typically triggered by overfeeding, a dead animal decomposing unnoticed, or disruption of the filter. This is different from green cloudiness (algae bloom), which indicates excessive light and nutrients. White cloudiness is not immediately harmful but indicates elevated organic load and potentially elevated ammonia.
Action: Test parameters immediately. Perform a 30% water change. Stop feeding for 2–3 days. Check for dead or dying animals. Do not clean the filter (this will make it worse). Do not add clarifying chemicals — they clump bacteria and clog filter media. The bloom typically clears within 2–5 days as the bacterial population self-regulates. Ensure adequate surface agitation for oxygenation during this period.
Everything you need to understand aquarium water chemistry — from absolute beginners to experienced breeders.
GH stands for General Hardness and measures the total concentration of dissolved calcium (Ca²⁺) and magnesium (Mg²⁺) ions in your water. These are the two primary minerals that make water "hard." GH does not measure iron, sodium, or other minerals — only calcium and magnesium.
GH is measured in degrees of hardness (°dGH) or ppm (parts per million). With liquid drop test kits, each drop = 1°dGH = 17.86 ppm.
| Classification | Drops (°dGH) | PPM | Suitable For |
|---|---|---|---|
| Very Soft | 0–3 | 0–54 | Discus, Cardinals, Neon Tetras |
| Soft | 4–6 | 71–107 | Crystal Red / Taiwan Bee Shrimp |
| Medium Hard | 6–10 | 107–179 | Cherry Shrimp, Community Fish |
| Hard | 10–15 | 179–268 | Guppies, Mollies, Livebearers |
| Very Hard | 15+ | 268+ | African Cichlids, Rift Lake species |
Precision tools to plan water changes, dose remineralizers, and preview parameter changes before you touch the tank.
The most common cause of parameter-related shrimp deaths is not ignorance — it is acting on incomplete information. A hobbyist notices their GH is too low, reaches for the remineralizer, adds what seems like a reasonable amount, and accidentally overshoots by three drops. Or they perform a large water change to reduce nitrates without accounting for the fact that their replacement water has a different GH than the tank, accidentally crashing their carefully maintained Caridina parameters.
These four calculators exist to eliminate that guesswork entirely. Before you touch your tank, you can calculate exactly how much water to change, precisely how many grams of remineralizer to add, and predict exactly what your parameters will read after the change. The Tap Water Advisor takes this a step further by assessing whether your tap water is even suitable for your chosen species — saving beginners months of trial and error.
Many sensitive species — particularly all Caridina shrimp and Sulawesi Cardinals — cannot be kept successfully in tap water. Their parameter requirements are so specific, and tap water chemistry so variable and unpredictable, that the only reliable approach is to start with a blank canvas: RO/DI (Reverse Osmosis / Deionised) water, which has a GH of 0, KH of 0, TDS near 0, and pH around 6.5–7.0.
From this blank canvas, you add back precisely the minerals your species requires using a remineralizer formulated for their needs. This approach gives you complete, reproducible control over water chemistry that is simply not achievable with tap water. The Remineralizer Dose Calculator makes this process exact — no more guessing, no more test-and-adjust cycles that stress your animals.
Fill in tank size and parameters to see your water change plan.