Back siphon

[ellisz]

Hi all,

Due to a recent power outage, I realized my return line is back siphoning back into the sump. I have a megaflo overflow and it has a small hole in the 90 fitting before the return outlet. It is siphoning up to the level of my return though. This is too close for comfort.

Do you think I just need to make the hole bigger?

Any thoughts would be great!

[scuba_steve]

add a small hole on your return the same way i guess ya have on your overflow if i read this right

[Overstocker]

I figured no matter how big the hole was it will get clogged. I keep my return nozzle close to the top of the water line for the just in case the hole does get clogged. The chamber from my mega flow will drain down over time also, because the return pipe is not "sealed" at the bottom either, it is just kinda snug fit into the bulkhead. I have tested by turning off the pump and letting it sit for a few hours to make sure everything possible could drain back (and fit) into the sump.

[cleantank]

You could install a check value to your return line

[ellisz]

That is the thing, there is a hole already on the return line. The wall of the overflow stops the water from draining down the durso style pipe. The return pipe comes up from the bottom of the tank and there is an elbow with the pipe that puts the water back into the tank.

On the return elbow, there is a small hole there already. You can hear the water shooting out while the pump is running. It is just above the water level. I wonder if this should be submerged?

I'll check the specs of the overflow. Did not do this before I moved the tank though ...

[scuba_steve]

being below the water line will help the water from splashing !! i have yet to have a hole clog up !!

[ellisz]

overstocker: Mine is just snug fitted too. I did check to see if the hole was clogged but it is ok. Maybe it did it before but I might have lowered my return nozzle when I moved the tank. I have been experimenting with different water flow direction.

If I shut the pump down and then lift the nozzle up, it stops draining.

clean tank: Good idea on the check valve but I have been told not to rely on one.

[scuba_steve]

check valve imo are a no no !!

[cleantank]

why?

[scuba_steve]

because they are prone to get clogged and/or stick open !! so if your set up is wrong when it sticks you will have a huge mess !! why ya make sure you have a big enough sump and/or set it up so when the pumps turned off it will will your sump without over flowing onto the floor and when your up and running your sump would be about half/3/4 full to make room for the back flush

[cleantank]

Every thing you have said is true, they do require more maintenance to keep them clean. To me, it's just another item on my maintenance list. Some folks cut it very close on overflow. To me it's just making sure. Well have got to run and maintenance some tanks, thanks for the discussion.

steve-aka cleantank