How Many Tetras Can 40G tank Hold

At least 30, if the betta is the only other thing you are planning on having in there. However, this does depend on the tetra - I'm working on tetras the size of neons or cardinals here.

-Imagines betta commanding army of tetra-
Type is important, neons stay small, some like penguins get pretty big. Also certain kinds (serpae, maybe others) should never be kept with a betta I believe.

+1. Serpaes are vicious little monsters.

i got 7 in the new tank gonna go buy some more today

What kind?

Olympia said:

What kind?

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neons

Neon tetras. If you have neons then you could easily have 45 neon tetras in there with a male betta

fishy friend2 said:

Neon tetras. If you have neons then you could easily have 45 neon tetras in there with a male betta

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ok say for my 30g with no betta just strictly neon tetras how man can i fit ?

I'd usually leave at least a gallon per fish.. Your betta may feel uncomfortable having that many fish around him, make sure there's a lot of plant for him to hide in.

Olympia said:

I'd usually leave at least a gallon per fish.. Your betta may feel uncomfortable having that many fish around him, make sure there's a lot of plant for him to hide in.

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im just gonna do all tetras in one tank and leave my betta in my 10g tank

An all tetra tank sounds cool
And spoiled Betta! xD

In a 30g with no betta, you could do 30-40 tetras.

I completely agree with the above post, 30-40 is a great number, but have you thought about cardinal tetras? They a much brighter and prettier In My Opinion, you could still have 25-30 easily in there

fishy friend2 said:

I completely agree with the above post, 30-40 is a great number, but have you thought about cardinal tetras? They a much brighter and prettier In My Opinion, you could still have 25-30 easily in there

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Actually yes i have i am gonna do all cardinals i went to my local pet store to check if they have any i did not succeed they said there getting a new batch of cardinals 1500 next friday so i will wait until then i cant wait

btw thank you all for the help

fishy friend2 said:

I completely agree with the above post, 30-40 is a great number, but have you thought about cardinal tetras? They a much brighter and prettier In My Opinion, you could still have 25-30 easily in there

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oh and are you saying 25-30 in a 40g or in a 30g ?

I think what FF2 meant was that you could fit 25-30 cardinals in the 30G but 30-40 neons

Moderator said:

I think what FF2 meant was that you could fit 25-30 cardinals in the 30G but 30-40 neons

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oh ok i thought he was talkin about the 40 ok cool thanks

I think 30-40 tetra of any of the "common" type is pushing it in a 30g tank. If the species is one of the quieter ones (i.e., not active swimmers) such as cardinal tetra then in a 30g I would not have more than 15 roughly. And no other mid-water fish; some substrate fish would be OK, and some surface fish like Carnegiella marthae (9-12). And lots of plants, or alternatively a more authentic habitat with sand, lots of wood btranches, and thick floating plants. Minimal filtration (cardinal do not like flowing water, nor light). Very soft and acidic water is mandatory. You can read more in our profile, click the shaded name.

Byron.