Shrimp do not die of the things people expect. They rarely starve and they rarely get eaten. They die from unstable mineral content and from molts that go wrong — which makes this small category of remineralizers, bacteria supplements and mineral foods the difference between a colony that breeds and a tank that slowly empties.
GH is the number that matters
General hardness — the calcium and magnesium in your water — is what a shrimp builds its new shell from. Too low and it cannot complete a molt; you find the shrimp dead, half out of its old shell, sometimes with a visible white band at the neck. Too high and molting becomes difficult in the other direction. Either way, the swings hurt more than the absolute number.
Rough targets: Neocaridina (cherry, blue dream, yellow, orange) want GH around 6–8 and are forgiving. Caridina (crystal reds, taiwan bees, tiger shrimp) want GH around 4–6, soft and acidic, and are not forgiving at all. San Diego tap is hard, which is why most people here run Caridina on RO water plus a remineralizer rather than trying to correct the tap.
Remineralizers come in two kinds
GH-only products add calcium and magnesium without carbonate hardness. This is what Caridina want, because they need soft water over active soil that is pulling pH down — adding KH would fight the soil.
GH+KH products add both, which is what Neocaridina prefer, since they do better with some buffering and a stable pH nearer neutral.
Buying the wrong one is a common and expensive mistake. Check which shrimp you keep before you check the price.
Biofilm is the actual food
Shrimp graze biofilm all day. Prepared foods are a supplement to that, not a replacement, and a new tank has almost none — which is why shrimp added to a freshly set-up tank often thin out over the first month even though the water tests fine. Bacteria and biofilm supplements exist to shorten that window by seeding the microbial layer early. In an established, mature, planted tank with lots of surface area, you need far less of everything.
Feed less than you think
Overfeeding is the leading cause of death in shrimp tanks, by a wide margin. A small colony needs a fraction of a pellet every other day, and anything left after two hours should come out. Uneaten food fuels a bacterial bloom, which crashes oxygen and takes the shrimp with it. Fast them one day a week; they will be fine and the tank will be better for it.
Copper
Copper-based medications kill invertebrates. Any ich treatment, snail treatment or fish medication containing copper is lethal in a shrimp tank — check the label every time, and never treat a shrimp tank with a fish medication without confirming it is invert-safe. This is the one rule with no exceptions.
Acclimating
Shrimp react to sudden changes in dissolved solids far more than to pH. Drip acclimate over an hour or more, do not rush it, and do not add the bag water to your tank. See our drip acclimation guide for the method.
Substrate for shrimp
Caridina keepers generally run an active buffering soil, which holds pH in the low 6s and does half the work of maintaining parameters. Shrimp-specific soils go a step further with added minerals and a granule size suited to shrimplets. See our substrates for the full range.
Bring a water sample
Almost every shrimp problem we diagnose in store is a parameter problem, and almost none of them are visible in the tank until it is late. Both stores test water for free — bring a sample and your TDS reading if you have a meter, and we will tell you whether you need a remineralizer, a different one, or nothing at all. More on species and setup on our freshwater shrimp page.
