i have a goldfish in my tank with guppies, and alsorts of others, the temp is 77 and he is happy as larry. been in there for 6 months now, so i say, yes, u can keep goldfish in a heated tank!Rue said:Fan-tails? As in goldfish?
You can't mix goldfish (cold-water) with live-bearers (warm-water).
Why are you planning on breeding fish?