How to prevent a back-siphon of FW into sump on Tunze ATO. (reservoir sits higher than sump)

[Crabs McJones]

Once you start a siphon into sump with ato pump how would a hole in res stop siphon (ato to sump). ttubing not in sump so no back siphon

Basically my sump sits lower then my ATO reservoir. So if you put a hole in the hose inside the reservoir it creates an air break so that instead of siphoning freshwater into your sump, the air breaks the siphon and stops it from continually draining freshwater into my system.

 

[drtrash]

How large of a hole? Would love to use the Gus’s fitting on sump instead of running it up to overflow. Only issue with overflow is need to drill a hole in side so I can use lid

 

[Ross Petersen]

Basically my sump sits lower then my ATO reservoir. So if you put a hole in the hose inside the reservoir it creates an air break so that instead of siphoning freshwater into your sump, the air breaks the siphon and stops it from continually draining freshwater into my system.

Old thread... I might do this... with the only risk being that if the black tubing is not taught (excess tubing in the reservoire), it won't break the siphon if the hole is submerged (or the hole will extend outside of the reservoirs). Especially if I have friends maintaining when away...

Might just find a way to raise outlet in the sump.

 

[AZMSGT]

Old thread... I might do this... with the only risk being that if the black tubing is not taught (excess tubing in the reservoire), it won't break the siphon if the hole is submerged (or the hole will extend outside of the reservoirs). Especially if I have friends maintaining when away...

Might just find a way to raise outlet in the sump.

@Ross Petersen
When I was running this system, I found I could feed the ATO water into my tank direct. My ATO water return line was clamped to the rim of my tank up top just above the water surface. The ATO would pump water into the tank but the sump would still find it’s level and everything worked well.

 

[pelphrey]

I've always fed my ATO into a larger diameter hose as seen below with no siphon issues.

Tunze 3155 is the ATO I am using.

 

[Raptor72]

Yup. I’ve also done pretty much the same thing will all my tanks since I usually go with a 20 gal ATO reservoir. I buy some rigid clear tubing and place the ATO line inside. I make sure that the top ends up at least inch above the reservoir.

an