Last week I posted the question wether to go internal filter or external canister filter. I needed a to get something in a hurry so I got an internal filter after seeing one in action in somebody elses tank, have had it in for a couple of days now and it is making a difference. Thanks for all the feed back, it made me go out and read a bit more on sumps. Then it dawned on me that the soloution has been staring at me all the time! The tank I have was originally built to be a marine tank, in one of the corners it has been closed off and has 3 different chambers, the first chamber has a hole cut out thru the bottom, the second and third chamber is not completely closed off from eachother, I assume this is for water to flow from one to the other thru bio balls? See images below. I am assuming that this can be used for a tropical tank as well, my question is does anybody know what will be needed to set it up and how?! My tank is not anywhere near setup properly, the fish always move the gravel around and the air pipes are constantly lifting! Probably need to get alot more gravel on the bottom. I am moving house end of October and will have to empty the entire contents of the tank, I have read all the threads on moving tanks and the advice has come in very handy. When setting up the tank up at the new house I would like to get the filtration system up and running, a new stand and canopy, all has to be custom made by me and a few mates. I then want to spend some money on kitting the tank out with new plants, rocks, drift wood etc and a nice background picture, I also want to build some kind of rockery to hid the internal filter behind in a corner and just have the spray nozzle showing. So there is alot of work, but I'll take pics all the way and keep you posted.