A three-tier guide to freshwater dwarf shrimp - which species tolerate tap water, which need RODI plus active substrate, what tank size actually works for a self-sustaining colony, and why hard water kills Caridina but Neocaridina thrives in it. Written by the Fast Aquatics Husbandry Team.
Freshwater aquarium shrimp sort cleanly into three difficulty tiers based on their water-chemistry requirements. Getting the tier right matters more than which color morph you pick.
Tier 1 - Neocaridina davidi (easiest). Cherry Shrimp and all their color morphs (Blue Dream, Yellow Golden Back, Green Jade, Orange Sakura, Black Rose). Tolerate a pH range of 6.5 to 8.0, GH 6 to 15, KH 3 to 10, temperature 65 to 78 F. Most US municipal tap water works with just a dechlorinator. Breed in freshwater with no intervention. Colonies of 30 to 50 shrimp in a 10-gallon are self-sustaining.
Tier 2 - Amano Shrimp (medium difficulty). Caridina multidentata. Larger (up to 2 inches), the best algae eater in the dwarf shrimp category, tolerant of a wide parameter range similar to Neocaridina. The catch: Amano larvae require brackish water to develop, so they will not sustain a colony in a freshwater tank. Every Amano you own was wild-caught or bred in dedicated brackish larval systems. You are keeping individuals, not a colony.
Tier 3 - Caridina cantonensis (hardest). Crystal Red Shrimp, Crystal Black, Taiwan Bee (Blue Bolt, King Kong, Wine Red), and Tangerine Tiger crosses. Require pH 5.8 to 6.6 (acidic), GH 4 to 6 (soft), KH 0 to 1 (near-zero), temperature 68 to 74 F, and active substrate (soil that buffers pH downward) to maintain those parameters. Miss any of these and the colony dies within weeks. Reserved for keepers with 6 or more months of Neocaridina experience and a willingness to run RODI water.
Cherry Shrimp (Neocaridina davidi) is the entry point for 90 percent of new shrimp keepers, and rightfully so. Fast growth, prolific breeding (a mature female drops 20 to 30 eggs every 4 to 6 weeks), tolerance of most tap water, and a color range from bright red (Sakura, Fire Red, Painted Fire Red) through blue (Blue Dream, Blue Velvet), yellow (Yellow Golden Back, Neon Yellow), green (Green Jade), and black (Chocolate, Black Rose).
Tank size. The 5-gallon minimum you see cited on forums is a bare-viability number for a starter group of 6 to 10 shrimp. A 10-gallon is far better and lets you keep 30 to 50 shrimp long term with a stable bioload. Every doubling of tank size approximately doubles the sustainable colony size because water-quality swings dampen out with volume.
Water parameters (Neocaridina). pH 6.5 to 8.0 (they breed most reliably at 7.2 to 7.8), GH 6 to 15 dGH, KH 3 to 10 dKH, TDS 200 to 400 ppm, temperature 65 to 78 F. Test your tap water first with an API GH/KH kit before deciding whether to run tap or RODI. If your tap comes out inside these ranges after 24 hours of aging, tap plus dechlorinator is fine and cheaper than remineralized RODI.
Substrate. Inert substrate. Seachem Fluorite, CaribSea Eco-Complete, Estes Marine Sand, or plain pool filter sand all work. Do not use active substrates like ADA Amazonia in a Cherry tank; the pH crash to 5.8 to 6.2 that active substrates produce will kill your colony over 3 to 6 months as buffering wears off.
Feeding. Cherries graze on biofilm continuously and only need targeted feeding 2 to 3 times per week. Bacter AE (a powdered biofilm booster) once a week, plus small quantities of Shrimp King Complete or Hikari Shrimp Cuisine pellets, plus blanched vegetables (spinach, zucchini, cucumber) once a week. Overfeeding is the number one cause of Cherry colony crashes because uneaten food spikes ammonia in small tanks.
Breeding. This is where Cherry Shrimp become fun. A well-fed, well-kept Cherry colony doubles roughly every 3 to 4 months. Mature females (identified by the yellow or green "saddle" on their back, the developing ovaries) drop 20 to 30 fertilized eggs and carry them under the tail for 3 to 4 weeks before releasing fully-formed miniature shrimp. No larval stage, no special breeding tank required. If you see any berried females (eggs visible under the tail), your parameters are correct.
Pricing tiers. Sakura Cherry (basic grade, some patchy color): 2 to 4 dollars each. Fire Red (uniform red top to bottom): 5 to 8 dollars. Painted Fire Red (deepest red, includes legs and rostrum): 8 to 12 dollars. Blue Dream, Green Jade, and premium color morphs run 6 to 15 dollars per shrimp. Colonies typically start with 10 to 20 shrimp, so budget 40 to 200 dollars for the initial stocking.
Amano Shrimp (Caridina multidentata, formerly Caridina japonica) are the working shrimp of the planted tank world. Takashi Amano popularized them in the 1990s for algae control in Nature Aquariums, and they remain the most efficient dwarf shrimp for eating hair algae, staghorn algae, and film algae.
Size and appearance. Adult Amanos reach 1.6 to 2.0 inches, roughly 3x the mass of a Cherry Shrimp. Clear body with a dotted lateral line running head to tail. Females have longer dot patterns; males have shorter, rounder dots. They are much more visible in a planted tank than tiny Cherries and are frequently chosen for aquascape display alongside show fish.
Tank size. 10-gallon minimum, 20-gallon better. Amanos are grazers with large ranges. A group of 5 to 10 in a 20-gallon planted tank is the standard aquascape stocking. They will strip an algae outbreak from a mature planted tank within 3 to 5 days.
Water parameters. pH 6.5 to 7.5, GH 6 to 12, KH 2 to 8, temperature 68 to 78 F. Wider tolerance than Caridina but narrower than Neocaridina. Amanos do poorly in water hardness below GH 4 (they molt-crash) or above GH 14 (chronic stress and short lifespan).
Cannot breed in freshwater. This is the key operational fact about Amano Shrimp. Females carry eggs successfully, larvae hatch, but the zoea require brackish water (specific gravity 1.010 to 1.024) to develop through 6 molts over 40 to 60 days before they metamorphose into juvenile shrimp that can return to freshwater. Every Amano sold in North America is either wild-caught from Japan or Taiwan, or bred in dedicated brackish larval systems by specialty breeders. This is why Amano pricing has not dropped much in 20 years.
Pricing. 5 to 8 dollars per Amano at hobby stores, 3 to 5 dollars in bulk from wholesale suppliers. Import shortages caused prices to spike to 12 dollars in 2023-2024. Buy in groups of 5 to 10 for meaningful algae control.
Crystal Red Shrimp (Caridina cantonensis) and the wider Bee Shrimp family are where dwarf shrimp keeping becomes precision hobby. Every parameter matters, mistakes are quick, and the grade system rewards subtle pattern differences with 20x price multipliers.
Why hard water kills Caridina. Wild Caridina cantonensis live in blackwater streams draining tropical mountain forests - soft, acidic, mineral-poor. Their gill physiology is adapted to move ions inward from that low-ion environment. High-hardness water forces their gills to work in reverse, driving ion regulation into failure over weeks to months. This is why Caridina die in hard tap water even when pH and temperature look correct.
Water parameters (Caridina). pH 5.8 to 6.6 (mandatory acidic), GH 4 to 6 (mandatory soft), KH 0 to 1 dKH (near-zero buffering so active substrate can pull pH down), TDS 100 to 150 ppm, temperature 68 to 74 F. Never above 76 F sustained; Caridina crash at reef-tank temperatures.
RODI plus remineralization is mandatory. You cannot mix your way to Caridina parameters with tap water. You need reverse-osmosis-deionization water at 0 TDS, then add Salty Shrimp Bee Shrimp Mineral GH+ (not GH/KH+) at approximately 8 to 10 grams per 25 liters to hit GH 5, TDS 130, and KH near-zero. A 5-stage RO/DI unit runs 150 to 250 dollars. Salty Shrimp GH+ is 30 dollars per 850g package and lasts a year for a 10-gallon tank.
Active substrate is mandatory. ADA Amazonia (the original, or Amazonia V2), Fluval Stratum, or Brightwell Aquatics Rio Escuro. These substrates contain humic acids and buffering compounds that pull pH into the 5.8 to 6.4 range and hold it there for 12 to 18 months. Expect to replace substrate on that cycle. Inert substrate (sand or gravel) cannot maintain Caridina parameters because there is nothing pulling pH down against the natural drift toward 7.0.
The color grade system. Crystal Red grades run from C-grade (mostly clear body with scattered red) at 15 to 25 dollars, through B-grade and A-grade with progressively higher red coverage, to S-grade (heavy red pattern) at 40 to 80 dollars, SS-grade (Mosura pattern named for solid red bands) at 60 to 150 dollars, and SSS-grade (Crown, Hinomaru, or Flower Head patterns) at 100 to 400 dollars. Taiwan Bee lines (Blue Bolt, King Kong, Wine Red, Panda) run 30 to 300 dollars per shrimp depending on pattern and breeder lineage.
Breeding. Caridina breed in freshwater like Neocaridina if parameters are correct. Berried females carry 20 to 30 eggs for about 30 days at 72 F. Juveniles hatch fully formed with adult coloration. But the tolerance for parameter drift is tiny - a TDS swing from 130 to 180 during a water change can trigger colony-wide molt failure and multiple deaths.
The single biggest cause of Caridina colony crashes is putting them on inert substrate. The Cherry Shrimp forum answer of "any substrate is fine" applies only to Neocaridina. For Caridina, the substrate is what maintains the water chemistry.
Inert substrates (Seachem Fluorite, CaribSea Eco-Complete, pool filter sand, plain gravel) do not affect pH or hardness. They are the correct choice for Neocaridina tanks where you want pH 7.2 to 7.8 held by KH buffering. Cost 15 to 40 dollars for a 20-pound bag; last essentially forever.
Active substrates (ADA Amazonia V2, Fluval Stratum, Brightwell Rio Escuro, Landen Shrimp Soil) are volcanic soils treated with humic acids. They pull pH down to 5.8 to 6.4, buffer against hardness increases, and gradually leach until exhausted (typically 12 to 18 months). Required for Caridina. Cost 30 to 65 dollars per 9-liter bag; a 10-gallon tank uses one bag.
The mistake pattern. New Caridina keepers buy shrimp before they understand active substrate. They put Crystal Reds on Fluorite, watch parameters drift up over 2 months, and lose the entire colony. Or they use expired active substrate (over 18 months) and see the same drift. Test TDS, GH, and pH weekly on Caridina tanks; if any parameter is drifting outside spec, the substrate is exhausted or was wrong for the species.
The default answer is: nothing. A shrimp-only tank produces the largest colony and the least stress on the shrimp. If you must add tankmates, the guiding rule is that any fish with a mouth larger than an adult shrimp will eat baby shrimp until the colony is gone, even if it ignores adults.
Banned tankmates for shrimp colonies: angelfish, gourami, cichlids (any), betta (they hunt juvenile shrimp specifically), tetras larger than 1 inch, barbs (nippy), goldfish (predatory and pollution-heavy), any loach that eats snails (they eat baby shrimp too), assassin snails.
Tolerable tankmates (adults survive, juveniles get eaten): small tetras (ember, chili rasboras, celestial pearl danios), Otocinclus, small Corydoras, small snails (nerite, mystery, ramshorn). Colony will grow slowly because juveniles are cropped, but adults remain safe.
Truly shrimp-safe tankmates: other shrimp species of similar size (do not mix Neocaridina color morphs unless you want them to hybridize back to brown wild-type), nerite snails, mystery snails. Nothing else with a mouth.
Cross-species hybridization is the one non-predator risk. Different Neocaridina davidi color morphs (Cherry, Blue Dream, Yellow Golden Back) will freely interbreed and their offspring revert to brown wild-type within 2 generations. If you want your colors to breed true, keep only one color per tank. Neocaridina and Caridina do not cross-breed.
Shrimp graze biofilm and microalgae continuously. Targeted feeding supplements this baseline diet but never replaces it. In a mature tank with 4 to 6 weeks of biofilm buildup, shrimp can survive with zero targeted feeding for weeks.
Weekly feeding schedule. Bacter AE (SL-Aqua or GlasGarten) once a week - a tiny pinch dusted on the water surface. This is bacteria and biofilm food, not shrimp food directly, and it seeds the substrate with the microorganisms shrimp eat. Shrimp King Complete or Hikari Shrimp Cuisine pellets 2 to 3 times a week - one small pellet per 10 shrimp, remove uneaten portion after 4 hours. Blanched vegetables (30 seconds in boiling water then cooled) once a week - spinach, zucchini slice, cucumber slice, weight down with a fork.
Overfeeding kills colonies. The single most common Cherry colony death pattern: new keeper feeds daily to "make sure they eat," uneaten food decomposes in the substrate, ammonia and nitrite spike in the small tank volume, entire colony dies over 3 to 5 days. Feed less than you think, especially in tanks under 10 gallons.
Do not feed when berried females are close to release. Adult shrimp will eat baby shrimp if hungry. A well-established biofilm plus a mildly underfed adult population produces the best baby survival rates.
Shrimp are extremely sensitive to sudden changes in TDS and pH. A shrimp that ships fine and arrives alive can die within 30 minutes of being dumped into a tank with different parameters. The drip acclimation procedure is not optional.
Procedure. Float the sealed shipping bag in the destination tank for 15 minutes to equalize temperature within 1 F. Open the bag and gently pour the shrimp plus shipping water into a clean container (a 1-quart deli container or a small bucket) positioned below the tank's water level. Run air-line tubing from the display, tied with a knot or set with a plastic drip valve to 2 to 3 drops per second, and start the siphon into the acclimation container. Drip until the original shipping water volume has been tripled - typically 90 to 120 minutes. Test TDS or GH in the acclimation container against the display tank; parameters should match within 2 dGH and 30 TDS ppm before transfer. Net the shrimp into the display; never pour shipping water into the tank.
Why 2 hours is the floor. Shipping bags accumulate ammonia over 2 to 3 days of transit. Opening the bag raises pH slightly as CO2 escapes, which converts stored ammonium (safe) to free ammonia (toxic). Slow drip dilutes the concentration gradually. Fast acclimation lets the ammonia spike hit the shrimp before dilution takes effect.
DOA policy. If any shrimp arrives dead in the bag, photograph it in the sealed bag immediately, before opening. Most reputable vendors (Fast Aquatics vendors included) require in-bag photos for DOA claims within 2 hours of delivery.
Cherry Shrimp (Neocaridina davidi) is the standard beginner shrimp. They tolerate a pH range of 6.5 to 8.0, a hardness range of GH 6 to 15, and most US municipal tap water works fine with a dechlorinator like Prime or ChlorGuard. Start with 10 to 15 shrimp in a 10-gallon planted tank on inert substrate; a healthy colony doubles every 3 to 4 months.
Yes, but the colony will not grow. Any fish with a mouth larger than a full-grown shrimp will hunt juveniles. Shrimp-tolerant tankmates include chili rasboras, ember tetras, small Corydoras, Otocinclus, and nerite snails. Banned: bettas, angelfish, gouramis, most tetras larger than 1 inch, and any cichlid. For maximum colony growth, keep shrimp-only.
Only for Caridina species (Crystal Red, Bee Shrimp, Taiwan Bee). Neocaridina (Cherry Shrimp and their color morphs) do fine on aged tap water plus dechlorinator if your tap tests inside GH 6 to 15 and pH 6.5 to 8.0. Test your tap with an API GH/KH kit first. If your tap is outside these ranges or heavily chlorinated with chloramine, RODI plus Salty Shrimp GH+ remineralization is cheaper long term than fighting your tap.
Most likely one of three causes: hard water (Crystal Reds require GH 4 to 6 and TDS 100 to 150; tap water almost always fails this), wrong substrate (inert substrate cannot hold pH at the required 5.8 to 6.4, so it drifts up and stresses the colony), or exhausted active substrate (ADA Amazonia buffers for 12 to 18 months then stops). Test TDS, GH, and pH weekly on Caridina tanks and replace substrate on schedule.
The commonly cited number is 10 shrimp per gallon at maximum stocking, but healthy colonies function at 3 to 5 per gallon with less water-parameter fluctuation. A 10-gallon tank can support 30 to 50 shrimp comfortably. Amanos need more room per animal because of their larger size; 5 Amanos per 10 gallons is typical planted-tank stocking.
Amano Shrimp cannot complete their larval development in freshwater. Females carry eggs successfully and larvae hatch, but the zoea stage requires brackish water at specific gravity 1.010 to 1.024 for 40 to 60 days across 6 molts. In a freshwater tank the larvae die within days. This is why every Amano sold in the US is either wild-caught or bred in dedicated brackish larval systems by specialty breeders.
Yes, and longer than for fish. A shrimp tank should be fully cycled (0 ammonia, 0 nitrite, some nitrate) AND have 4 to 6 weeks of biofilm development before shrimp arrive. Shrimp graze biofilm continuously; a tank without established biofilm forces them to survive on targeted feeding alone, which is a poor substitute. Set the tank up with substrate, plants, and cycled filter media, then wait a month before ordering shrimp.
Two different genera adapted to different water chemistries. Neocaridina (Cherry Shrimp and their color morphs) evolved in Taiwan streams with medium-hard neutral water and tolerate a wide range of tank conditions. Caridina (Crystal Red, Bee Shrimp, Amano) evolved in soft acidic blackwater or tropical streams and require specific parameters that differ by species. Never keep both in the same tank; they will not cross-breed but they compete for the same food and each does better under its own optimum parameters.
Sourcing matters more for shrimp than for fish because health and color grade vary enormously by breeder. The dependable sources:
Specialized shrimp breeders: The Shrimp Farm, Aqua Huna, Flip Aquatics, Buce Plant, Rachel O'Leary Invertebrates, Msjinkzd. All ship live shrimp with guarantee coverage. Prices are higher than Petco but the shrimp are healthy, correctly identified, and quarantined before shipping.
Fast Aquatics vendor network: Multiple Fast Aquatics vendors carry Neocaridina and Caridina lines with lineage documentation and Living Guarantee coverage. Filter the freshwater catalog for shrimp listings.
Avoid: generic pet-store shrimp shipped without ID, and eBay lots without breeder identification. Cheaper up front, but health issues and low color grade cost you 6 to 12 months of colony development.
Pair your shrimp order with our step-by-step setup tutorials and the stocking calculator to plan the tank before the shrimp arrive. Browse all beginner pick guides for parallel species starting points.