On sunday I almost bought an expensive overflow off eBay but I lost the auction, then yesterday I got an idea to just use a simple gravel vaccum and a small jar to create an overflow box.. er overflow cylinder! I just wanted to try hooking up my aquarium to another small one, and i dont need a huge flow rate or a huge gygantic overflow box hanging over my aquarium. So here you go:
1 Gravel Vaccum with hose (cost ~$10)
1 Thin cup like thing (I used a spice jar)
All you do is put the jar down the cylinder, and feed the tube coming from the overflow inside your aquarium into the jar. The jar will preserve the cyphon, and water just flows over it and down the cylinder!
I added some plastic bits underneith to keep the jar from falling right to the bottom. It works quite well! Might be a good idea to seal the cylinder and the green cap with some silicon. If you need a tube to go from the overflow on the back to the one inside your aquarium you can just cut a small length off your gravel vaccum tube.
Also I drilled a hole at the top of the cylinder for a hook to hang on the aquarium.
Heres the picture
Heres my crappy overflow from inside the aquarium, made out of a spent bottle of Buckleys with holes drilled into it. I need to add some more holes and fasten it better with some proper dudads but I havent figured out best how to do this. I havent secured the tubes either so Im going to turn it off until i fasten them properly.
Anyway this was fun.