thanks for your help. that all sounds easy enough, now ive just got to go get the water! pies, I LOVE YOUR TANK! and you would probably be dissapointed in mine as i am just starting out. you might have seen it, its in the pet store in nelson. its not really mine, it belongs to the store. we're trying to do things right, with the sump etc instead of just using a canister filter. no protein skimmer on it yet, thinking of getting a deltec though. the tank is still cycling at the moment. the poor clowns in the shop are in a little 70lt tank at the moment-they will be going in the big tank once its all cycled. i feel so sorry for them in their little tank. ill try posting some diatom coverd pictures, ill just go read how to post pics now. thanks dudes.