oh wait, i totally misread how you designed it. I didn't realize you were using the large tube for air AND water. I thought it was the style with the airline as the "float valve". Didn't realize all that airline in the pic was just a ghetto-rig to tie the stuff up, haha. Nice! Anyways, it's a nice and simple design. Other than the salinity thing, and the fact that it's not adjustable, that thing'll work like a charm forever. But for god's sake, make it less ghetto! haha. You don't even need to spend anything, just clean up what you have, maybe get rid of the airline straps, and get the label off the bottle nice w/ rubbing alcohol.