Based upon the design by others listed here and elsewhere. Built for under 10 by a coworker.

http://img.photobucket.com/albums/v607/cruisaire/Picture002.jpg

does it employ a floatswitch?

so what did you use from each of the plans?

can you post a more blurry pic? :lol:

ATO as in Automatic Top Off?

can you provide a link for the design?

Here is how it is made from what I can see. If i had to bet I would say that there is probably an electronic float switch wired into the air pump which you can get here:

http://www.aquahub.com/store/ifloatfloatswitch.html

You wire that switch into the power cord of the air pump so that it turns on when it gets down to a certain level and off when it is full. Then you drill a hole in the water bottle and put a fitting on it so you can seal the hole. You can even just drill the hole the diameter of the hose and use caulk to seal it. Then you drill a hole in the top and run an air hose down all the way to the bottom of the bottle. Then seal the hole in the top and run the hose to the tank. When the air pump kicks on it pushes water up the output and into the tank. Its pretty simple but for 10 bucks you could also buy an aqua lifter and run it fron any size container. I dont know how much water it puts out in relation to the aqua lifter tho. Good simple way tho with stuff you can pick up at wal mart :)

does it employ a floatswitch?

Yep, same one we use for groundwater remediation. I'll get a part number, supplier, and prices and list here.

http://www.nano-reef.com/forums/index.php?act=Attach&type=post&id=1366

Very cool.

They should note not to have the waterline of the reservoir above the waterline of the display tank, or it will drain due to siphon. Also, the vertical distance the air pump is able to pump the water will be extremely limited by the pressure produced by the air pump.

Just saw this, but it looks like a lot of trouble and more money.

http://www.aquahub.com/store/diygaquarium.html

^^^ That's actually where I bought my float switch. The mold-a-holder is very convenient!