hey all i am new to the whole fish keeping scene i recently purchased a 21 litre hexagon tank and have had a few fish come and go mostly going which is not good but at present i had one gold fish in the tank but yesterday i purchased another small goldfish and 2 zebra danios as i asked the sales assisitant if i could mix the fish in my tank he said that as the zebra danios were of a good size that this should be alright. I got them home and they all seem to be enjoying there new home is there anything that i should be aware of in keeping these new species of fish.
thanks graham