al&burke
Active Member
I set up a 36 gallon tank for an ATO resevoir. The sump is 15 inches high and the resevoir is 17. This goes against the rules of an ATO - essentially if the reservoir is higher than the sump the ATO will continue to add water by natural siphon once the ATO pump is off. So i wanted a larger ATO that would last for more than 3 weeks (approximately) I added a 7 inch tall stub of 1" pvc pipe open top/bottom. Secured it very well to the sump and inserted the ATO supply line to the top of the 1" diamter pipe. So when the ATO pump shuts off the siphon is stopped because it is a lot higher than the height of the resevoir. Just thought I would share.