How many fish in a 75 gallon tank?

A group of angelfish or discus with a school, or a rainbowfish and barb community.

A 75 gallon is 48 x 18 inches, the same length as a 55 but 5 inches deeper front to back. That extra width is why it is the usual recommendation for angelfish, discus and medium cichlids.

Stockings that work in a 75 gallon tank

Each mix has been run through the stocking calculator and comes out with no problems or warnings.

Angelfish with bleeding heart tetras and corydoras
4 × Angelfish, 10 × Bleeding heart tetra, 8 × Sterba's cory.
87% stocked
A discus group
6 × Discus.
75% stocked
An electric yellow lab colony, hard water
12 × Electric yellow lab.
66% stocked
Denison barbs with a bristlenose pleco
8 × Denison barb, 1 × Bristlenose pleco.
54% stocked
Three fancy goldfish
3 × Fancy goldfish.
70% stocked

Try your own fish

Neon tetras schooling above corydoras catfish in a planted tank

Why not one inch of fish per gallon

That old rule says to allow one inch of adult fish per gallon. It is easy to remember and works well for small, slim fish like tetras and rasboras.

It breaks down for bigger and messier fish. A fish twice as long weighs several times as much, and goldfish and plecos make far more waste than their length suggests. Our calculator keeps the inch rule for fish under three inches and counts larger fish for more.

At this size the limit is usually temperament and water, not volume. Discus want water near 86°F, African cichlids want hard alkaline water, and neither mixes with a standard community.

One kind of fish, nothing else

The most of each that suits a 75 gallon on its own.

Neon tetra	up to 88
Guppy	up to 44
Harlequin rasbora	up to 59
Cherry barb	up to 53
Platy	up to 53
Panda cory	up to 53
Bronze cory	up to 35
Honey gourami	up to 6
Pearl gourami	up to 4
Tiger barb	up to 44
Angelfish	up to 6
Fancy goldfish	up to 4
Bristlenose pleco	1 only
Electric yellow lab	up to 18
Discus	up to 8

Before you add the last fish

Add fish slowly. A new tank needs weeks to grow the bacteria that process waste, so add a few fish at a time.
Count the minimum group. Schooling fish are stressed alone, so plan around the smallest group before the tank total.
Plan for adult size. Fish in the shop are usually young.
Match the filter. Look for one rated for 300 to 450 gallons per hour.

A full tank is not a target. One at 60 to 80% is easier to keep clean and gives fish room to settle.

Sizes and weight: 75 gallon tank dimensions.

Common questions

How many fish can live in a 75 gallon tank?

A group of angelfish or discus with a school, or a rainbowfish and barb community. The example mixes on this page come out between 54% and 87% stocked by our calculator, with no warnings.

How many neon tetras fit in a 75 gallon tank?

Up to 88 neon tetras in a 75 gallon with nothing else in it. Add other species and that number comes down.

Is one inch of fish per gallon a good rule?

It works for slim fish under about three inches, such as tetras and rasboras. It fails for larger or messier fish, because a fish twice as long has several times the body mass. Count big fish for more.

What size filter does a 75 gallon tank need?

One rated for 300 to 450 gallons per hour, which turns the water over four to six times an hour.

Gear for a 75 gallon tank

Searches on Amazon for the right size. Check the tank size or flow rating on the listing before you buy.

Heater, 300 WSized for a normal room.Filter, 300 to 450 gphA canister or sump suits a tank this size.Stand, 48 x 18 in or largerMust support the whole bottom frame.Lid or hood, 48 x 18 inKeeps fish in and slows evaporation.Water test kitTracks ammonia, nitrite and nitrate.Water conditionerRemoves chlorine from tap water.

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