would this physically work for top off?

[rig]

Its been a while since i took physics, but would this idea work.. Instead of dealing with a submersible pump, you could simply drill 2 holes in the top of some water bottle (a nalgene maybe), even a coke bottle, and then have to lengths of airline tubing going into it. One would go all the the way to just off the bottom, the other just below the top. When the the top off switch activates, it would turn on an air pump which would pump air into the bottle ( 90% full of water) via the tubing that only barely goes into the bottle. Would this force the water up the other length of tubing and back into the tank? I am wanting to do this because I want the return on my top off to be via tiny airline tubing rather than the bulky 1/4" tubing that you have to attach to the powerheads if you use those instead. Anyway, lemme know what you think, maybe this was just very dumb.

[Chamkeeper]

There is a company, TUNZE, I think, that make a 'pumpless' design top off, but the source is 5 Gallons. It would be pretty simple to scale down to nano size.

 

Reefcentral had some plans I think.

[willtel]

Yep it will work. I just made one out of a small drink container like you said. I am still waiting on the float switch but I tested it wih the air pump and it works great. At first I was worried that the air pump wouldn't have enough power to push the water up to the tank but after I plugged it in it spewed water about 5' out of the tube until the lid blew off!! I'm going to need to get an air valve so I can tune the pump down and it should work fine. I'll post some pics when I get it all set up. I also plan to mix kalk with my water and use it to dose.

[rig]

what power air pump did you use? Glad it works, cant wait to see pics.

[LakerFan]

I kinda like this idea more than a PH to pump water back into the tank. An air pump running without water sounds a whole lot nicer than a PH without water too. Now I have something else to do!

 

Also, I don't think I have to worry about a back syphon with this setup. ( I can put the return tubing under the water line) As long as I have one of those one-way check valves for the airline coming in from the pump. Am I right in assuming that????

 

I have a 3 gallon jug at home, I think I'm going to see how far up an my spare air pump can push some that water.

 

Thanks for the idea, and shouldn't this be in another forum? at least not lighting:P

[willtel]

Ok guys, I snapped a few pics. They aren't much but it should make a little more sense now that we can see it.

 

Here is the bottle with the tubes and cap installed.

Here is a shot of the lid.

Here is the pump I am using.

Making a mess in my roommates bathroom:P

 

After this I attached a piece of airline to the output and draped it over the shower rod, the pump moaned a little but it had enough power to get it up an over the bar. About 5 feet. The only issue I am having is with the top blowing off my bottle. I think I may be able to use a valve and turn the pump down a little to solve that. If not I will be looking for another bottle with a screw top. One of these from Nalgene labware would be sweet but they are like $100!! Anyone know a cheaper source? Also this thread would be better in the Do it Yourself forum.