Siphon break for ATO

[Salty hands]

I'm looking to use electronic float switches to turn on a mj1200 for an Auto Top off system. Because the reservoir is above the level of my sump, a siphon is created when the pump shuts off and will flood the tank, killing all inhabitants. (Almost happened)

I think it was Jimmyj7090 that advised me to use the siphon and gravity feed the water, controlled by a couple solenoid valves in series for ATO. While this is a good idea, I wonder how reliable these mechanical parts would be. Plus it's not inexpensive.

Does anyone know if a dishwasher air gap would work as a siphon break? This should break the siphon when the pumps not on. It seems like a simple and reliable design. Any one try this?

 

[smcnally]

Just put the end of the hose from your MJ1200 above the waterline and your problem will be solved.

 

[NateHanson]

Just put the end of the hose from your MJ1200 above the waterline and your problem will be solved.

His reservoir is above his sump, so the siphon goes through the pump, into the sump. What you're suggesting would work if he could raise the output hose above the level of the reservoir, but I'm guessing that is not feasible, unless the reservoir and sump are at nearly the same level.

I don't know what a dishwasher air gap is, but you can get an anti-siphon loop from a marine supply store. They come in various sizes, and you get the one that fits your hose diameter. It's an upside down U-shaped pipe with a joker valve at the top (sometimes called a reed valve) that lets air in when the pipe is under suction, but closes when the pipe is under pressure.

 

[NateHanson]

http://www.defender.com/product.jsp?path=-1|51|106370|316448|316445&id=102633

 

[smcnally]

Ah...I read his post wrong

I would ditch the MJ then, put a drain in the bottom of the reservoir, and put a sprinkler valve on the hose. Providing energy opens the valve and killing power closes it. I've been using one on my tank for well over 2 years with no issues. They look like this and can be bought at Lowe's for about $18.

 

[Dragon2115]

I don't know the physical layout of your stuff but if the placement of the reservoir/sump allows it there's a cheap way to fix this. Take a piece of pvc pipe of appropriate size that's long enough to be taller than the reservoir and stand it up in the sump vertically. Take the flex line coming from the MJ and put it into the top of the pvc pipe and secure it so it won't fall out but not so that it's air tight. That's it. The Mj will pump water into the pvc pipe which will drain into the sump. Where there isn't an air tight seal between the flex line and the pvc a siphon can't be formed. You can add a "T" at the bottom of the pipe so the outlet isn't stuck in the sand.

Redneck Engineering to rescue. Their moto, "Wrinkles in your duct tape is a sure sign of poor craftsmanship."

 

[Salty hands]

Steve, Nate and Dragon - all good ideas. The height delta between the sump and reservoir is about 3 1/2 feet. So the PVC might not be a great solution in this case; ingenious though. The anti-siphon also appears that it would do the job. The sprinkler valve looks like a great solution for this application. When it's closed, it's shuts off the water supply, when it's open - gravity feeds the sump. Two concerns come up: the reservoir will be a kalkwasser solution - will this affect the reliability of the valve? Does the valve close tight?

The dishwasher air gap is still a viable solution. Clogging wouldn't be a big concern since it deals with the discharge of a dishwasher I assume it can handle kalk.

 

[stevenp]

What about mounting one of these in your sump, fed by a line coming from the bottom of your reservoir? I've seen other members use them successfully, but I'm not sure if any were using them in Kalk.

 

[Salty hands]

Jimmj7090 indicated these were annoyingly prone to clogging when using kalk. Otherwise a good choice.

 

[NateHanson]

I wouldn't use the kent valve. They have a pinhole outlet that clogs very quickly with kalk. However, the USPlastic.com float valve (about 1/4 the price) is much better. I used that for years without clogging.

I would not rely on any single flow-control for an ATO though. Personally I'd use a solenoid valve (mcmaster.com) or the sprinkler solenoid valve, AND a mechanical float valve in the sump.

 

[Aquadiva]

Redneck Engineering to rescue. Their moto, "Wrinkles in your duct tape is a sure sign of poor craftsmanship."

Jim, that's too damn funny.

 

[bluehd60]

i had the sam problem i just used a small piece of acrylic drilled for a bulkhead, a bulkhead and a piece of pvc . i glued it to the corner of the tank and it works fine. just as long as it is higher than the reservior level and it doesnt go into the water. i will post a pic soon.

 

[bluehd60]

here is a pic

 

[MVIT]

Just drill a small hole in your tube coming from your maxjet feedline. drill it at about your kalk reservoirs top. When your pump comes on it will feed your sump as normal except it will squirt a little back into the kalk tank (keeping it mixed too)and when the pump shuts down the siphon will be broken by the small hole. If you size the hole about 1/8" it should not clog. This would be a really cheap workaround. I would test it in a bucket first though.