Inside of the chambers there are adjustable downtubes thru which water returns to the reservoir after being sprayed on the roots. Push the tubes down, the water in the chambers goes down. Pull the tubes up, and water in the chamber goes higher. That is why I strongly suggest you just go out and buy one instead of building your own. You can get them for around $300 on the net. I have three aeroflo's and like them pretty well. No leaks or other crap you have to deal with on a homemade system.
I've seen pics of Stinkbuds homemade system and don't care for it; it seems to allow too much light to get into the res which will lead to problems with algae.
I've seen pics of Stinkbuds homemade system and don't care for it; it seems to allow too much light to get into the res which will lead to problems with algae.