for goldfish, room temperature is great and they can aclimate to slow changing moderately cool water. if the water is to warm, the tank starts to smell.
for some fun, get cheap bigger goldfish and throw in a crayfish. my old crayfish tried to hunt down the goldfish.the goldfish might get eaten but the crayfish i used to have didnt eat them. he did however clip of the tail of one of my goldfish but it grew back.
for some fun, get cheap bigger goldfish and throw in a crayfish. my old crayfish tried to hunt down the goldfish.the goldfish might get eaten but the crayfish i used to have didnt eat them. he did however clip of the tail of one of my goldfish but it grew back.