I want to know exactly how it works and I how can make one

DIY Guide to ATO

http://www.nano-reef.com/search/q.php?cx=p...&sa=Go#1009



I am about to give the air powered ATO a shot. 10$...

http://www.nano-reef.com/forums/index.php?showtopic=29093

I have an air powered one just like in that thread and it works great. Of course I took it to an extreme. I have a 5g container and it has to lift the water about 3 feet but it will do it. One sugestion though, get a back up battery pump that has a cord, so that it only turns on when the power is out, Then you can put it on a timer so that it won'e come on at night and wake you up if it's in your room.