alright, so until i get another heater, i have my old one that i used on my 29gal in my 75. i have no idea how many watts it is, but i think that it was meant for up to 55gals? anyways, i put all of my fish (one at a time) into my 75 today. the temp is around 75 and rising. i'll have it at 80 before i go to bed tonight. but anyways, i had my male socolofi in the tank for about an hour before adding the other fish because he was being picked on. anyways, he got bigger real quick, but is still small compared to the female. . . (unless both are females? idk, but only the big one has had eggs, even though the little one has more eggspots. . . ?) but so far they seem to love the bigness of the tank!