right now i have 3 molly boy fish and 1 molly girl fish (and one molly girl fry in her own tank about 2 months old) (i had the correct ratio but some died) all are in a ten gallon, i recently gave my goldfish away to a bigger tank so they can be happy and want to put the boy mollies in the ten gallon tank the goldfish were in but my mom won't let me buy a heater especially since i am upgrading to a bigger tank once i give away my three boy mollies and i will need a different heater. so can i keep them in this tank without a heater for maybe like 2 months? or should i just give them away first?