I've just come back from the fish shop as I went to get some tropicals for my 100 ltr set up. When speaking to them they said i could only take a few fish today as its a new tank and you cant put them in all in at once. I had the idea that I wanted neon tetras but was told that i couldn't until other fish had been in there for a month. I wanted to get some small while silvery fish, cant remember the name. He also said you have to buy one species at a time. Is this correct? Anyway we settled on Pengiun Tetras as our first fish and could only buy 3 for some reason. We have been told to give them a few days in the tank then to come back and buy some more!! Should they be saying this? Surely this is wrong information as its gonna take ages to fill up my tank!! The Pengiun Tetras are so tiny it takes a while to find them in my tank, i would of thought we would of been allowed a little more.