I just purchased a femal ballon molly for my 10 gallon tank. The guy at the pet store said that she might be pregnant, how would I know if she was? Also the filter I got was to strong and seemed to be sucking her into it, could she be hurt? One last thing, I was thinking about keeping her with definitly at least 1 more molly, maybe 2 otto's and 2-3 glowfish danio's. Do you think that would be to much? Also, could the otto's&danio's live in the slightly salty tank?

Thanks!


P.S, it's going to be a planted tank

I really hope she's pregnant, if she isn't then chances are she's sick. Right now she's just staying in one place and isn't swimming very well. Are mollies strong swimmers?

Balloon mollies have mutated so that they already look like little balloons. That makes it very hard to tell if one is pregnant or has a problem like dropsy. I've never had mollies myself but have seen the little balloon mollies at the store. Being deformed, balloon mollies will have more trouble swimming and avoiding filter intakes. You can cover the filter intake with a sponge-type filter to dissipate the suction over a larger area or otherwise try to block the intake from the fish. Balloon mollies are weak swimmers. Her staying in one place may mean she just has trouble swimming from the balloon deformity or could indicate she's ill. It's hard to tell.

The 10 gallon is large enough for the fish you mentioned. Ottos and zebra danios (glofish are genetically altered zebra danios) don't like a lot of salt, especially the ottos. You would have to put the salt at a level so as not to bother the little catfish (ottos) but enough to help the mollies. That might be something like a tablespoon of aquarium salt per 3 gallons. The mollies really want more than that though. Also, the danios will be fast and might bother the mollies but I think they'd probably get alone.

Good luck!

What are some other fish I can keep with my molly in a 10 gallon tank?

Mollies are pretty compatible with similar livebearers like swordtails, guppies, and platies. If not for the high salt, they would get along with many small, calm fish like cory cats, some tetras, some danios, some barbs, etc. Few fish like a lot of salt. Most species I can think of that are brackish tend to be biosterous and nippy such as dwarf puffers, scats, monos, etc. Those last two also grow too big for your tank.

Thanks for the help! I think I would like to get 2 mollies, 2 platy's, 3 fancy guppies and 1 cory cat. Is that to much? If I got those fish how much salt should I put in? Currently I have put 2 tablespoons for my recently bought platy&2 molly's, should I add any more, or remove some? Sorry for all the questions!

That's not too many fish as long as you don't add them all at once. Cory catfish though really like to be in groups so, if you get them, get at least four. That would reduce how many other fish you could get. The cories would be the least salt tolerant, probably not happy to have more than a tablespoon per 3 or 4 gallons. The mollies like a few tablespoons per gallon but can do ok with less. I don't know too much about their preferred salinity levels.

If you have 2 tablespoons in 10 gallons right now, that level is ok for almost all freshwater fish. The mollies probably do want more but the platies are probably fine with it. I would wait a few weeks before adding more fish while your tank is cycling and monitor the ammonia and nitrite as well as the fish to see how they're doing.

Sadly Bubba (the first balloon molly) passed away this morning :(

I am sorry.