The short answer
Dwarf shrimp have such a tiny bioload that the usual rule of thumb is generous: roughly 2 to 5 shrimp per litre once a tank is mature. A 20 litre tank can hold a thriving colony of 40+ cherry shrimp, and a 10 litre nano still supports a small breeding group. Because shrimp waste so little, the limit is rarely the number of shrimp — it’s water stability and grazing surface.
Why shrimp are the exception
Most stocking maths is about waste. Fish are messy; shrimp are not. They eat biofilm, algae and leftover food, and produce almost nothing that stresses the filter. That’s why you can keep them at densities that would be reckless with fish. What they need instead is stable parameters — steady temperature, low nitrates and no sudden swings — plus plenty of plants, moss and hardscape to graze and hide among.
Sensible shrimp stocking
- Starter colony: 10–15 cherry shrimp in a cycled 20 litre — they’ll multiply
- Nano colony: 6–8 shrimp in a mature, planted 10 litre
- Algae crew in a community: a few amano shrimp alongside peaceful fish
If you keep shrimp with fish, remember many fish eat shrimplets — see which tankmates are safe below.
Before you stock
Set up the tank for stable water — a mature, planted, gently filtered tank suits shrimp best. Read what aquarium shrimp eat, choose safe companions with what fish can live with shrimp, and see the best shrimp tankmates. Cycle first via how to cycle an aquarium, and browse the aquariums hub for a suitable nano.