Back Siphon Question

[Patrick Cox]

I have a 57G Rimless that is predrilled with an internal overflow and when I turn off the power to the pump, I am getting back siphon into the sump which is causing too much water to flow back into the sump. What can I do about this? The attached picture is not exactly how I have this setup now but it is close. The balljoint output tube is now split into a Y and I have tried to raise the output as close to the surface as possible but I am still getting more siphon than I would like. Should I drill a hole in the ball joint output tube? If so, where?

Thanks,
Pat

 

[Maivortex]

The easiest thing to do would be just elevate the output of the ball joint. If this is not an option You can drill at the highest point of the ball joint and connect a small piece of tubing that will go up a few inches. This maybe noisy, so I would loop the smal piece of tubing back down into the tank. You want the tubing submerged only about 1/2 inch so it sucks air when the tank level goes down 1/2 inch. This should break the siphon.

 

[sneaton]

drill a siphon hole on your return right below your water line

 

[sjm817]

The water will drain down the the bottom of the overflow teeth and also jist below the level of your return outlet. The return outlet is way too low in that pic. If you position it near the surface, and the water level is only draining to the bottom of the overflow teeth, you dont have enough reserve capacity in you sump to contain the drainback and you will need to correct that..

 

[Patrick Cox]

The water will drain down the the bottom of the overflow teeth and also jist below the level of your return outlet. The return outlet is way too low in that pic. If you position it near the surface, and the water level is only draining to the bottom of the overflow teeth, you dont have enough reserve capacity in you sump to contain the drainback and you will need to correct that..

Thanks, yes, I understand that the return was too low in this picture. The reason for that was that I was getting cyclones in the water if the return was any closer to the surface. So, I ended up adding a y fitting to my return output to reduce the force of the water coming out of the nozzel and also to get better flow in the tank. With the fitting I now have on the end of the output, the return still needs to be about 1" below the surface. This can work with my sump from an overflow perspective but it is very close and I would prefer to break the siphon earlier.

On drilling a hole in the return, how does this impact the flow? Does this just mean that some of the output will exit through this hole? Any other concerns / issues with this?

Thanks!
Pat

 

[sjm817]

When you shut everything down, does the level drop below the bottom of the overflow teeth? If it doesn't, reducing the return back siphon wont make much of a difference. If it does, you can try the anti siphon hole. You can drill it in the plumbing up high inside the overflow. Yes, water will squirt out of it so be careful where you put it. I'm not crazy about these as they can clog and stop working.

 

[sneaton]

my anti siphon hole has saved me three times this year.....just drill it angled down or to the side so it dosent squirt up