need ATO Help??

[Tom K]

Just set up my ATO and I thought I knew what I was doing. The problem is when the float trips the pump off, the water still flows into sump. Must have created a siphon. I don't understand how.

Plastic barrel for res. about 15" wide 3 Ft high holds about 20 gal.
Sump, 30 gal, water level is about 8" high
Brand "X" pump in res, about the size of a Mag 5
1/2" pvc from pump to sump. PVC ends about 4" above water level of the sump.

Why is this happening, and what can I do to Fix??

 

[NYreefNoob]

it could be syphoning, is the hose angled downwards ?

 

[junglebase]

Try using a smaller size pump to transfer the water.. that pump looks too strong and it creates a continuous siphon, that is the only thing i can think of.. it looks like you had it set up correctly...

 

[boardryder]

http://www.melevsreef.com/plumbing/auto_topoff.html
Make sure the hose going into the tank is not submurged in water. If the pump goes on opposite of how you want it you wired it backwards. Rewire it. Everything sound correct though.

 

[KathyC]

I might be off the mark here..but if the water in the top off tank is higher than your sump..once you start that siphon..it's going to keep on going...

 

[FREEZE]

three things: 1. make sure your pump in the ato reservoir is below/lower than the end of the return line in the sump (otherwise you will get syphoning). 2. make sure your return line in the sump is above the water line. 3. That sounds like a really strong pump for this application. In the event of a mishap that pump will move a lot of water in a short period of time. If you have a spare one switch to a smaller return pump (something like an mj400).
good luck.

 

[boardryder]

I use a tom aquatic and it is perfect for the job. Though I only have a 46 gallon, I think it would suffice for much larger tanks and sumps. Better to be safe and use something that pumps in about 5 gph than 300 gph.

 

[jim63dt]

I had a problem if I filled my res too high It would continue to flow try lowering the water in your res and than trip the float see if that works