Ato pickup placement

[csterling86]

I've got a tank I built very close to the same specs of a 40 gal breeder with a 10 gallon sump.i made my weir off an old over the top overflow box an drilled a single 1 1/4 drain.im wondering if the pickup for the ato would best suited in the tank or sump? Or the weir I see some ppl placing it in there as well.i really wanted it in the sump but it seems it would be more stable in the tank an not be cutting on an off all the time.just wondering who has had the best results an where.in my sump as it's setup my last return chamber doesn't change water level unless my weir gets close to running empty an starts sucking air then flow slows but that is so close to running dry I don't like it.so I'm thinking in the sump it would be doing a lot of off an on.

 

[blaxsun]

If you have a sump that's the best (and really only) choice.

 

[Indymann99]

If you have a sump your ATO floats/sensors should be in the RETURN section. The ATO pump output can go in any section of the sump.