How many fish can happily live together?

Question

I have a ten gallon freshwater tank that sits at 79 degrees. It's got a live plant in it and it's fully cycled. I have four harlequin rasboras and three albino corys, and I would like to add some neon tetras. How many could I add? Or if you have a suggestion for another fish, that would be good too.

Answer 1

Your tank is not overcrowded if you have a good filter and the water is circulating well.  You should also be doing 30% water changes every week.

That said, you could add a half dozen neons without any problems.  Neons are so small, they do not pose much of a burden on the bio-system.  The 4 harlequins might get a little nippy with the neons, but the corys will not be a problem.  Just provide some extra plants for the neons to swim in and out of and you should have no problems.

Congratulations on keeping the 3 corys, most people don't know that corys should be kept in groups of at least 3... more is better.

8

Answer 2

No more.

Tetras really need to be in a group of five or more to get the full schooling effect, and that would be way too many.  

Put in another plant and let it go.

Answer 3

With the number of fish you have you are already maxed out (10gal is really too small for 3 cories)    

Answer 4

you could add 3 or 4 tetras, and the bioload would be maxed out.

a good alternative would be fancy guppies, 2 or 3 of them, is about equivolant to 3 or 4 neons, and the males have beautiful colors

people say that " 1 inch of fish per gallon" is the norm, and this is totally wrong. that rule can only apply to tetra like fish. so if a person says " you've got (insert number here) inches of fish, so you can add (insert quantity of fish)" would be wrong. the cories have more bioload than a tetra the same length