Mez you need your tank set up and pump running for a good few days before you put fish in.. the most important thing in a tank is Bacteria in the pump and it takes a while too build up, you can put some in out of bottles, but time is best, NEVER let any soap/chemicals anywhere near your tank, they will kill the bacteria and then your fish
even if you have washed your hands in anti-bacterial soap and then put your finger in the water....POORLY fish...
Your pump will be a Fluvel 2, which are TOP pumps, a little pump with carbon filters in it would be good as an extra. Carbon 'polishes' the water and makes it really clear..
Enjoy.