How many fish?

[Sky]

I have a 13 Gallon Hexagonal Tank containing 2 Black Mollies, 2 Dwarf Coral Platies and 4 Zebra Danios. Everything seems to be extremely happy at the moment. Have I room for 5 Neon Tetras or should I stick with what I have got?

 

[OohFeeshy]

Hmmm... I'd say no... It's one inch of fish /gallon usually..

 

[Fish_first]

I would think i'd be okay, neons are small and stay small, they aren't messy either, so not an overload to the bioload. However that would be the last fish I would add.

 

[sylvia]

Mollies get to 4" and are messy. Zebra danios need the swimming space. I don't know about the 'dwarf' coral platies. What size are they supposed to get to? All the livebearers, if of opposite sexes, will produce fry and over-stock the tank eventualy so I hope they are all male. Neons are small but need to be in groups of 6 at least. They are also fragile if water quality deteriorates - something that can easily happen in an over-stocked tank (which is something it would be with the neons in there). The fact that your tank is hexagonal also means the surface area is less than a rectangular tang of the same volume. This means less gas exchange and that, strictly speaking, means fewer fish. Consider the displacement caused by gravel/ornaments, you only have about 11 gallons, maybe a little more, maybe a little less. The fish you have at the moment have your tank fully stocked. Your danios should be in at least a 20 gallon, at least a long tank (which a hexagonal tank is not) so do them the favour and give them all the space they can get.