How Many Shrimp Can You Keep Per Gallon?
Short answer: Start with about 1 shrimp per gallon: roughly 5 in a 5-gallon, 10 in a 10-gallon. Cherry shrimp are tiny and low-waste, so colonies multiply well past that; real tanks run up to 5+ per gallon. A shrimp-only tank has no hard cap and self-limits to its food and biofilm.
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Planning a Cherry shrimp tank. We start with your cherry shrimp and filter the list to compatible tankmates — untick to see every species (incompatible ones get flagged).
Stocking — under 85% comfortable · 85–100% full · over 100% overstocked
Show the math
Start with about 1 shrimp per gallon: roughly 5 in a 5-gallon, 10 in a 10-gallon. Cherry shrimp are tiny and produce little waste, so a colony multiplies well past that starting number. A shrimp-only tank has no hard stocking cap the way a fish tank does. It self-limits to the food and biofilm available.
How many shrimp per gallon, by tank size
These are the counts real keepers actually run, from 48 tanks where they reported both the tank size and how many shrimp they keep (part of 71 shrimp stocking reports).
| Tank size | Typical shrimp (median) | Reported range |
|---|---|---|
| Up to 5 gallons | 5 | 2–30 |
| 6–10 gallons | 5 | 2–40 |
| 11–20 gallons | 8 | 5–50 |
| 21–40 gallons | 15 | 5–45 |
The median works out to roughly 0.9 shrimp per gallon at the starting count, but established colonies reach far higher: tanks in the data run up to 6 shrimp per gallon (for example 30 in a 5-gallon). Keepers buy a starter group, and the colony does the rest.
Why shrimp break the “per gallon” rule
The old inch-per-gallon idea is built for fish. Shrimp are different:
- Tiny bioload. A cherry shrimp is under an inch and eats almost nothing, so dozens add less waste than a single small fish.
- Self-regulating colony. A shrimp population grows to match its food and surface biofilm, then levels off. It does not keep climbing until the tank crashes.
- The limit is stability, not space. What caps a colony is steady parameters (especially GH/KH and clean water), not a gallon count.
How many shrimp is too many?
This is the most-asked shrimp stocking question on Reddit (How many shrimp is too many?, 420+ upvotes; So, how many shrimp is too many for a 2.5?). The honest answer: in a shrimp-only tank you rarely hit a hard wall. Feed lightly, keep GH/KH and nitrate steady, and let the colony find its own level. Problems come from overfeeding and unstable water, not from the shrimp count itself.
With fish, plan differently
Once fish share the tank, they add most of the bioload, and some will eat shrimp. Plan the fish stocking first, then add a shrimp colony in a planted tank with cover. A betta, for example, may pick off a few shrimp. See what fish can live with bettas, and check the combined load in the calculator below.
How we counted
Counts come from declarative posts (“I keep [N] shrimp in a [size] tank”) on r/shrimptank and related subreddits, with questions and hypotheticals excluded. N = 48 tanks with both size and count (of 71 shrimp stocking reports). Real example tanks: 10 shrimp in a 10-gallon and a 50-gallon colony. How we collect this.
Cherry shrimp at a glance
- Scientific name
- Neocaridina davidi
- Adult size
- ~0.6″
- Temperature
- 65–80°F
- pH
- 6.5–8
- Minimum tank
- 5 gal
- Temperament
- peaceful
- Social
- schooling — keep 6+
- Reference
- Wikipedia
Gear for this setup
As an Amazon Associate AquaGauge earns from qualifying purchases. Some links below are affiliate links, at no extra cost to you. Current price and availability are shown on Amazon. Disclosure.
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Hikari Shrimp Cuisine A purpose-made sinking diet for cherry shrimp that lets you feed small amounts so water stays stable in a crowded colony. Check price on Amazon → -
SaltyShrimp Shrimp Mineral GH/KH+ (100g) Sets steady GH and KH so your Neocaridina molt cleanly and the colony keeps breeding. Check price on Amazon → -
AQUANEAT Bio Sponge Filter (3 Pack, up to 10 Gal) Gentle sponge intake that biofilters the tank without sucking up tiny shrimplets. Check price on Amazon →
FAQ
- How many shrimp can I put in a 5-gallon tank?
- Start with about 5 cherry shrimp in a 5-gallon, the median real keepers use. They breed, so the colony grows to fill the tank's food and biofilm supply. Reported 5-gallon colonies in our data range from a few up to 30.
- How many shrimp in a 10-gallon tank?
- Around 10 to start (about 1 per gallon). A healthy 10-gallon colony commonly settles at 20 to 40 shrimp as it establishes.
- Can you have too many shrimp?
- A shrimp-only tank rarely overstocks the way a fish tank does. Shrimp are tiny and low-waste, so the real limit is food, biofilm, and stable water, not a per-gallon number. Watch parameters and feed lightly.
- How many shrimp per gallon is safe with fish?
- Fewer, because fish add most of the bioload and some eat shrimp. Plan the fish first, then add a shrimp colony. Check the combined load in the stocking calculator below.