Auto Top off siphon

Hi,

I put together an auto top off for my tank and I used an aqualifter pump to top off in the sump. The fresh water container for top off was on the ground and the pump was higher up and this was working for a week or so, Now the pump is failing to pump the water up all the way and if I place the water container higher up it pumps it up just fine except it creates a siphon and the water keeps flowing into my sump. Any way to prevent the siphon?

 

Auto Top offs need to be set or they will not work properly. I put a dab of crazy glue on the regulator suction cup so it wouldn't fall off. I use a small Rio pump and it works fine. Ques: How tall is your sump? I believe they call it head room that defines how far water can go uphill. I also attached the ATO hose to where I have the hoses going in from my UV sterilizer without letting the hose get too long. I had a flood when I first tried because the hose touched the water and when that happens the water keeps flowing out. Here are some pictures of mine. Maybe it will help you. Good luck!
PM me for any questions.

 

You need to make sure there is an air gap between the end of the hose and the water level in your sump. Also, pumps are better at pushing water than pulling it, so the pump should be in the freshwater reservoir.

 

You are better off keeping it level with the sump. Get a slightly stronger pump if you need to, this way there is no chance for a siphon to start with it being higher.

Big thing though.....poke a hole in the tube!!!!!!! This will break any siphon. Just make sure its in a spot where the ATO container can catch it.

 

I think ccscscpc is right on the money when suggesting the pump is slightly undersized. As the water level in your top off bin drops, the transfer pump has to work harder since the pressure of the deeper water is no longer helping it. If the pump was just a bit stronger it would lift the water all the way to the top of the bin and over into your sump... from there gravity will complete the job. Also be sure to leave a gap between the water level and the end of the tube, and secure it as the others have suggested.

Regarding the siphon you've described, any time the water level in your top off bin is higher than the end of the top off tube in your sump, the water will continue to flow until the level in the top off bin is at the same height of the end of the tube, maybe even if you put a small hole in the tubing near the pump. The hole can't really hurt, unless it's spraying water on the floor, but it isn't going to prevent a siphon if it is ever submerged or gets clogged somehow.

I personally think your best bet is to get a slightly larger pump instead of fabricating a siphon break. It's less effort, less prone to failure, and then the only thing you need to worry about is securing your tubing so that there is always an air gap between it and the sump's water level.

 

Is this a toms aqualifter pump?

If so it shouldn't have any problem pumping up to 3'. If you need to go up about a foot or so from the bucket to the sump I would put the pump on the top of the top off bucket and have the out hose going the rest of the way. If its close to 3' or more I would put the pump half way between the bucket and how far it has to go up.

I know toms aqualifters are not supposed to create back siphon, I assumed it would stop a forward siphon as well. Interesting to know it doesn't.

 

You know what - I completely missed that it was an Aqualifter. While it's still possible that it's undersized and that is why it isn't working just the way you want, I don't know whether an Aqualifter is prone to forward siphoning. Therefore my comments below may not be applicable to the Aqualifter. Sorry!

In fact, on an Aqualifter a hole in the tubing near the pump will indeed cause a problem, as it will either prevent suction on the input side, or create a puddle on the floor (or in expensive equipment) on the output side.

Keep playing around with the position and maybe you'll find a position that works well.

 

ok, now I have a better idea thanks everyone for your comments, Ill have to play around with it and see what I come up with.

 

Put a small PVC pipe into your sump. Put the end of the water tubing from the ATO pump into the top of the PVC pipe but not all the way into the water. Make sure the end of the hose is higher up than the ATO water reservoir.

 

Do you have any pictures? I have my Toms Aqualifter about 3 feet away from my sump. It is on the ground and draws water from a 5 gallon bucket that stays full because my RO unit is hooked up to it with a float switch. So it goes like this...water is sucked through hose about 2 feet out of the top of the 5 gallon bucket by the aqualifter which is on the ground next to the bucket. Then goes about 3 feet through a hose that I have zip tied to plumbing above my sump. That hose ends up about 6 inches above my water line in the return chamber of my sump. So no siphon is possible, this works fine. That Aqualifter pump is pretty good stuff!