I had Orandas for years, in Ohio, where I didn't have to worry about water temperatures being too warm. I'm now in Maui and have a 30g freshwater aquarium (gouramis, neons, etc.) and the water temperature stays about 78. I worried that's too warm for Orandas. I'd like to get a second tank and I see that you can get "chillers" for salt-water aquariums. Anybody have any experience using these for Oranda, Fancy Goldfish, etc.? What's the optimal temperature for Orandas?

Any type of goldfish prefer cooler water. You can go almost to freezing, or up to about maybe around 70F. We have a pond in our backyard. The water can get as high as 75F, and low enough to where the pond freezes over. They still live. They will probably do best at room temp, but you can go a little higher, or lower.

My son has a 55g with a couple Walleye and and a Sauger. He just took over cleaning the aquarium in a church classroom. It needs a lot of work. If anyone has any tips that would be great.

The tank had 5 inches of gravel and, as far as he knows, nobody changed any water, so the tank was full of slime.

United Methodist Church, Pierre, South Dakota

Orandas are by far my fav. goldfish.
I actually have one named Wanda!
anyway, you can own goldfish anywhere, you just need to be able to provide for their needs! They prefer temps. between 67 f. and 78. f. If it gets beyond 84 degreed you may want to consider a chiller, however most are able to live at room temperature.