How Many Mollies In A 30 Gallon?

[smashtime105]

How many mollies would be happy in a 30 gallon? It is brackish and I have overfiltration. I am only doing mollies, not platies or swordtails because they are not brackish.

 

[nmonks]

Depends on the mollies. Sailfins, especially giant sailfins, need more space than black mollies or (God help us!) balloon mollies. I'd say three female and one male sailfin would be a good starting point here. Male sailfins are notoriously aggressive and while you can certainly go out and buy a bunch of them, you will almost certainly find that one becomes a bully and the others get damaged or even killed. With the smaller mollies, something around 3 males and 7 females would be about right. In any event, you want to make sure the females outnumber the males if you want any chance of a peaceful aquarium.

By the way, both platies and swordtails will tolerate brackish water at the low end. SG 1.003 does them no harm at all, and is certainly less harmful than keeping them in soft, acidic freshwater. With care and patience, you may be able to acclimate them to SG 1.005. Mollies don't need more than SG 1.003 if you're using a decent brand of marine salt mix with carbonate hardness included.

Cheers, Neale

 

[smashtime105]

Depends on the mollies. Sailfins, especially giant sailfins, need more space than black mollies or (God help us!) balloon mollies. I'd say three female and one male sailfin would be a good starting point here. Male sailfins are notoriously aggressive and while you can certainly go out and buy a bunch of them, you will almost certainly find that one becomes a bully and the others get damaged or even killed. With the smaller mollies, something around 3 males and 7 females would be about right. In any event, you want to make sure the females outnumber the males if you want any chance of a peaceful aquarium.

By the way, both platies and swordtails will tolerate brackish water at the low end. SG 1.003 does them no harm at all, and is certainly less harmful than keeping them in soft, acidic freshwater. With care and patience, you may be able to acclimate them to SG 1.005. Mollies don't need more than SG 1.003 if you're using a decent brand of marine salt mix with carbonate hardness included.

Cheers, Neale

Awesome. I think my store only sells balloon and "regular" mollies. Not sailfins, however if I see some, I will probably buy the sailfins.