Reservoir keeps draining after pump is off

I’m trying to automate my watering for outdoor, have a 40 gallon reservoir, submersible pump, going to 1/2” tubing. Watering 9 plants, 4 SIP containers where it just fills a reservoir. 5 fabric pots fitted with “rain rings “ i made out of same 1/2” tubing.
The problem is that if i run the pump for lets say 2 minutes,(660 gph pump), that should be about 11 gallons or so. But the water keeps coming out after the pump is off and eventually the reservoir will be empty. Its not coming out with much pressure, it’s just like it’s siphoning out or something. Have I created a vacuum/air lock type thing or something? Anyone know where I’ve went wrong.

You can buy a anti siphon valve to put in the line somewhere. Or have the rez and pump lower then the plants then it won't siphon.

greentree420 said:

You can buy a anti siphon valve to put in the line somewhere. Or have the rez and pump lower then the plants then it won't siphon.

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The pump is on the bottom of the reservoir making it ground level , with about a 3.5ft rise out of the reservoir. So it’s already lower than the plants. I’ll look up anti siphon valve.

The point were its draining, is it lower than the point or place you want water to stay. Gravity will automatically if their is a way out lower let all the water out, even if it is through a switched off pump. Can you draw a diagram of whats happening and all exit and entry points aswell as pump. Thanks

TheWholeTruth said:

The point were its draining, is it lower than the point or place you want water to stay. Gravity will automatically if their is a way out lower let all the water out, even if it is through a switched off pump. Can you draw a diagram of whats happening and all exit and entry points aswell as pump. Thanks

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it is not lower anywhere the water is leaking out. The reservoir is a 45 gallon rolling plastic trash can approximately 3-4ft tall. So the water actually has to be pumped up that high. That why it seems like a vacuum or suction or voodoo or something other than gravity. I can try to so a sketch but it’ll be tomorrow before i can do that

SBNDB said:

it is not lower anywhere the water is leaking out. The reservoir is a 45 gallon rolling plastic trash can approximately 3-4ft tall. So the water actually has to be pumped up that high. That why it seems like a vacuum or suction or voodoo or something other than gravity. I can try to so a sketch but it’ll be tomorrow before i can do that

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If your pumping upwards to the reservoir. When that pump pumping upwards goes off the water will go back down. Its difficult to imagine exactly how you have everything, so im trying to go by what your describing . A sketch from start of water source to the end were it gets to the plants will help. Thanks.

You can poke a hole in your watering line right above the full level on the reservoir.
It will spray a bit of water when the pump comes on but it will break the siphon once it turns off.

Sounds like the water level in your res is higher than the discharge points creating a siphon. Bakersfield's solution is a good one. If you poke a small hole in the hose coming out of the res, air will suck back into the hose when the pump shuts off breaking the siphon. The hole should be above the water line but still inside your res so that any spray will go back into the res.

Poke a hole in the line that goes to the reservoir, it will prevent siphoning when turned off

I'm glad I found this. I just built an auto watering system and have been running it for a week with no problem....BUT I only filled it with 20 gallons originally. Last night I filled it with 30 + gallons. My res. is a 32 gallon trash can. I made sure to have my manifolds above the res, but my water lines to the halos are not. So this morning when I checked. instead of being down about 3 gallons, I was down 12 gallons!! It's DTW so they got a nice flushing, and fortunately I have my drain hooked to a condensation pump so it took it all away.

I was trying to find a solution, and was thinking an anti siphon valve, but drilling a hole would be easier!! I guess that will make the pump work a little harder.

How big a hole??? It's 1/2' PVC with a 800 gph pump, feeding two 8 outlet Orbit manifolds.

This was what I found as a possible solution....Would it even work?




Here's a few pics of my setup...









I did install a check valve above the pump...

This is how I've done anti-siphon, just installed a simple Tee connector into the line at the top of the barrel where its pumped out, if you don't have your feed line higher than your feed run then you will want to modify that.

Your solution would be drill 1 or more holes into the bottom of that horizontal PVC pipe, that would allow air into the line once the pump kicks off, breaking the siphon.

Orbit makes an anti siphoning valve.

you can just install one of these at a high point in your line and you won't have to worry about loss of pressure from drilling holes. The 90 elbow on top of your Rez can be switched to a T and you can install it right there.

calvin.m16 said:

This is how I've done anti-siphon, just installed a simple Tee connector into the line at the top of the barrel where its pumped out, if you don't have your feed line higher than your feed run then you will want to modify that.
View attachment 5304847
Your solution would be drill 1 or more holes into the bottom of that horizontal PVC pipe, that would allow air into the line once the pump kicks off, breaking the siphon.
View attachment 5304848

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Yep. I melted a small hole with a finish nail and it did the trick.

I thought about doing a anti siphon valve, but this was easier and the pump is oversized so the extra little spray won't hurt a thing.

Thank you!!