Biggest fish for a 10 gallon??

I keep Golden Topminnows in my 10g.
 
I would go with a fish that doesn't exceed 4 inches. I kept a single pink convict in a 10 for more than a year. He grew to his max size of 4.5 inches. He appeared to be happy and healthy. He has been in a 90 for 5 months and shown no further growth nor any change in disposition.
 
A Dwarf Puffer. What about a paradice fish? too big? Maybe an oil cat fish they stay about 2.5" and do alot of hanging out more active in the dark
 
Dwarf Gouramis are really wonderful for a smaller tank. They use up the space really nicely, of course their coloration is naturally amazing, (but there are the other color morphs too), and they are intelligent. Just have to keep up on the water maintenance and hope they are good genetic stock, or that you purchase one who's not timid at a store and regularly pokes around looking for food, etc.

It's almost a guarantee if I put any food in that tank, he'll find it. I rarely have to worry about food uneaten/missed. And because they need vegetation, they can graze on algae wafers all day easily (and that tends to keep their digestion in good order so when they do eat protein, blood worms, flakes, they don't have intestinal problems.)
 
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