Thanks for the comments guys!

Fry Lover: Its the 4ft x 2ft x 18" one. They are starting to out grow it now. But thats ok, more of an excuse for me to get a bigger one! I only have an Rena XP3 filter which does a great job on its own. But there is a couple of powerheads on each side of the tank aswell just to give out some water movement and oxygen.

Dom: You should invest in the 2metre Rena tank. My brother has one and they are very nice. You can sometimes pick up a second hand one for around £500-£600, I've been tempted. Mine are breeding like mad atm too. Got about 5/6 tanks of fry.