fizzypopz

which algae eating fish can i hav in my tank with goldfish, at the moment i hav 1 red cap orando i got told otto's like cool water.

sirdarksol

Nope, otos don't like temperate water. In fact, they're probably the worst of the suckermouths to keep with goldfish, as they need really stable water temp and quality.
In fact, I have so far been unable to find any dedicated algae eaters that thrive in temperate water. I have definitely been looking, as I have a tank with a koi and a goldfish that I would love to have a cleaning crew for.
Amano shrimp love temperate water, as they come from similar water sources as goldfish. Unfortunately, goldfish are curious, and while shrimp may not normally be on the menu, some goldfish will eat anything. Just ask my comet; He Who Eats Snails (this is not a joke. I had a snail-free tank within a day of introducing him. He's better than a yoyo loach).

Barbrella

Really, you'd be better off using an Algae Magnet for this tank and reducing the number of hours the light is left on.

Any really good algae eaters, like many plecos, are likely to also latch on to your sleeping goldfish and start sucking their slime coat off.

Goldfish really shouldn't be kept with tropicals anyway.

gremlin

I have a chinese algae eater in my pond with my goldfish. With a 55 gallon tank, you should be ok with one, I repeat, ONE, chinese algae eater. Put at least 2, preferably 3, hidey hole caves around the bottom of the tank. You would also need to supplement the algae in the tank with algae wafers. I have found that the way to keep CAE's from being aggressive towards other fish is to make sure they have sufficient hidey holes and food. I have not had any aggression issues with cae's in my pond which had comet goldfish, mosquito fish, 3 cae's, 1 pleco, and 2 clown loaches (for the snails).