It would be too small I'm afraid, especially if it is to be mixed with another cichlid. You could possibly have the firemouth on it's own but I would be looking at a 35 gallon tank.
could you tell us the meausurments of this 25g tank fully please....... lenth/width/depth
as stated a small tank with different cichlids would not be good, drawf cichlids would be ok, or a single specimen tank
the lengths are L 81 x H 46 x W 31cm Im not a really big fan of dwarf cichlids and i know i would be limited to what ciclid i would put in but the 1s that caught my eye are juwel cichlids, t bars, convicts and firemouthes if any of these are fine to go in my tank please give me your views