I Failed Physics

[melvinudawl]

So, I've had my auto top off running out of a 5g pail with a submerged pump. I put in a 20g container and used the same submerged pump. Obvious thing happens. After the float switch triggers the pump off, a siphon results because the output from the top off is lower than the water level in the container. I switched to an aqualifter and now have it well above the water leves of the sump and the top off container. I have the output airline running into a 1/4" ID that is secured into and extends above my sump. To be safe I also put a little hole in the input line above the max waterline in the ro/di container.

No siphon appears to form now, flow stops when the pump disengages. Will this work ok? Do I need the hole?

Thanks!

 

[Playa-1]

I wouldn't use the hole in the input line, I don't see how that is serving any purpose. It sounds like it should work ok.

 

[melvinudawl]

While waiting for responses, I tried it without the hole and while the flow almost stops when the pump shuts off, there is still a slow siphon with a constant drip still going 15 min later. The hole was intended to stop any siphon from my top off reservoir to my sump and appears to to its job. Just want to make sure I get this right with the obvious risks involved.

Thanks again!

 

[NeveSSL]

Personally I just use an Aqualifter. They won't siphon or back-flow, which means I use it to push water into my kalk reactor and the topoff comes out of the top of the kalk reactor into my tank.

They should be around $20-$25 at a local store.

Brandon

 

[melvinudawl]

hmmm...I am using an aqualifter pump. Back flow shouldn't and doesn't appear to be a problem. I have the output tube entering into a larger diameter tube that extends 6" above my sump, so no chance for back siphoning there.

However, when i shut off the aqualifter right now, it DOES continue to disperse water, although at a much slower rate. When I put a hole in the input tube above the reservoir water line this behaviour stops and the water flow completely stops when the pump is shut off. Keep in mind even with the 6" tube on the output, it is still lower than the max water level I'd like to have in my reservoir.

I did this because I put a similar hole in the return line from my sump to prevent back siphoning. Any problem with having the hole in the input line?

 

[WaterKeeper]

Stay with the hole Mel. Using a vacuum break is the good way to stop a back siphon. An air gap, having the outlet hang in the air, is better but, short of that, a vacuum break hole, slightly submerged, works well.

 

[Playa-1]

I thought he said he had the outlet suspended above the tank and the reservoir. Maybe I misread something.

 

[WaterKeeper]

If it is above the water he can't have a siphon. Unless he has a steam carpet cleaner for a pump.

 

[Playa-1]

Maybe he has the pump above the sump but the discharge line in the water, Or maybe he's using a steam carpet cleaner for a pump

 

[IslandCrow]

Don't feel too dumb. I did the exact same thing, and I actually did pretty well in physics (well, until I took Engineering Physics in college). As stated, the hole should work fine, but a better way is just keep the outlet out of the water so there's nothing to siphon.

 

[melvinudawl]

The outlet is out of the water, but below the max fill level I'd like on my reservoir. The hole seems to be working fine.

Thanks everyone!