I have decided to create a 40 gallon community tank with 2 ryukin goldfish (or possibly two fantail or veiltail goldfish, instead). By searching the web, I know that White Cloud Mountain Minnows and some sort of danios is compatible with goldfish. But the thing is, I like having easily identifiable fish with names. For example, it's easy to tell fish like bettas apart, but it's not with minnows because they all practically look the same!

Anyways, Does anyone know any 'easily identifiable' fish that is compatible with ryukin goldfish? I like colorful fish, that I know won't be bait for growing goldfish.

Oh, thanks for the answer. So, what do you think about 4 ryukins in an almost 45 gallon tank (90cm L*45cm W*40cm H) with a 50 gallon filter? Do you think this is a good idea/should I change it to 3 goldfish instead? If so, how often should I clean it?

Hi Sparkly puffball,

As Cheri pointed out you will need a larger filter. Goldfish are extremely messy and so usually the recommendation is for the filter to be able to turn over the tank volume 10x in an hour, so usually if a tank is rated say 30 gallons, then a 300 gallon per hour filter would be best.
External filters are usually the best thing for goldfish as they can hold a lot of media for bacteria, and can deal with the waste from goldfish. But you could always run an external filter alongside an internal filter if you prefer. But overall with filtration you'll want something that can do 450 gph

Hi cheri alexander,
I was planning on getting an Aquaclear 50 Power filter which pumps up to 200 GPH, but know that you guys say, I am now going to get an Aquaclear 110 Power filter which pumps up to 500 GPH.