OMGtempestuousfury said:I just noticed that you have 7 goldifsh in a 30 L tank. I'm not quite sure how big that is, but I belive it is too small. Goldfish are very messy and when in small spaces and in large quantities this large amount of waste results in lots of stress and diseases. You might want to reconsider keeping a tank of goldfish unless you're sure they'll stay small.