Would this compact auto top off system work well?>

[mike31154]

Originally Posted by X-Treme

I don't have a picture, but I'll explain it. I use a glass wine carboy with the rubber stopper. Drill 2 holes in the stopper and get some thin rigid plastic tubing (the size that you can push airline tubing onto it. don't remember the size). Insert 1 peice of the tubing through one of the drilled holes (make sure the tube is a snug fit in the hole. ie. drill the hole 1 or 2 drill bit sizes too small) and push this peice of tubing all the way to the bottom of the carboy leaving about 2 inches sticking out the top. Insert another peice of tubing in the other hole so it is only though about 1 inch. Insert stopper into carboy VERY snugly. Run airline tubing from the tube that goes to the bottom of the carboy to your tank or sump. Run airline tubing from the other tube to an air pump. Hook the air pump to a float switch or (in my case) a timer. As the pump pumps air into the carboy and pressurizes it, it pushes water out from the bottom. I figured out how much evap I have in a day and figured out how much the pump will pump out in 1 min. Calculate how many minutes you need to run your air pump over the day, and set your timer. My timer runs for 1 minute 4 times a day. 12pm, 4pm, 8pm, and 12am. (not overnight because much less evap with no MH lighting on).

If this was too much or you REALLY don't understand, I can take some pics, but pics won't really explain how it works.

Neato, please elaborate on where the car boy sits (what level) in relation to your sump or tank, i.e. how much head pressure are we talking here that the air pump can overcome?

[X-Treme]

The carboy sits on the floor right beside my tank and pumps up to the tank (no sump), so from bottom of carboy to top of tank is about 4 feet. NO PROBLEMS whatsoever getting the water to move that far. When I re-fill the carboy, I must remove the top up line from in the tank because of gravity syphon. And when I turn the pump on the water starts to move out of the carboy immediately. When it's empty and I pull the stopper out to refill there is QUITE a pressure build up. The whole setup actually works QUITE well if I do say so myself.

I almost forgot....... YOU MUST PUT A CHECK VALVE IN THE AIR LINE TO THE CARBOY, so that the water doesn't syphon back down the hose from the tank.