We inherited a 30L biorb which had 2 goldfish in it in may . After doing some research and finding out biorb + goldfish= bad we rehomed the fishes into my friends garden pond where they will have enough space . Is there anything that will happily live in this biorb or am I wasting my time with it ? It does look nice but I don't want to give some poor fish a miserable life with no space and rubbish filtration