Firemouths will probably work in a tank that size. What's the footprint? If you get 4 juvies that should eventually pair off, the only probablem is I've had 3 for almost a year and JUST now had them pair off and I couldn't imagine them at the size they are now with all three in my 29 that I have(that's why I asked for the foot print of your 30 gallon, since if my 29 were a tad longer I could see it being ok).
For a pair though, a 29 gallon would work, and so I suppose a 30 gallon would too.
BTW, FM's are awesome fish and they have great personalities. If possible try to get a few fish from different sources, that way you will hopefully get an unrelated pair, and thus produce fry with better genetics.
For a pair though, a 29 gallon would work, and so I suppose a 30 gallon would too.
BTW, FM's are awesome fish and they have great personalities. If possible try to get a few fish from different sources, that way you will hopefully get an unrelated pair, and thus produce fry with better genetics.