Help! New tank overflowing when pump off.

[LagunaGlide]

I’m setting up a new tank, and just filled it. This morning I turned on the return pump to see if the water level was enough. It was low, so I shut it back down, walked away and heard a noise.

Turns out it’s flowing through the return and into the sump so much that it overflowed the sump.

I don’t have check valves because they fail, and I have the return nozzles aimed down, and in fact I had them even lower than the bottom of the weir. I could raise the nozzles, but I’m using gyres and don’t need them up for surface agitation, but could be useful to move water under rocks etc.

Is this a combination of drain line depth in the sump, and return nozzles too low?

I don’t know how to fix this and could really use some help preventing this.

 

[Utubereefer]

Check valves can fail but they work more often than they don’t. Use a check valve

 

[Tommy B]

If the return nozzles are too low they will siphon water back down when the pump turns off.

I don't have a check valve on mine, but I did do some tests to make sure my return was at a ideal height so it wont overflow when it does siphon water back down.

 

[LagunaGlide]

Check valves can fail but they work more often than they don’t. Use a check valve

Any harm in just installing a single check valve in the soft line at the pump?

And IF it fails I’m back in this situation? Any redundancy / backup for a failed check valve?

 

[Utubereefer]

Have you ever had a check valve fail? It is a rare occurrence. I would definitely install one on your soft plumbing

 

[LagunaGlide]

Have you ever had a check valve fail? It is a rare occurrence. I would definitely install one on your soft plumbing

I have not. This is my first system with a sump of this type. Honestly, the only reason I omitted them is because of what I have read here, and other places about them failing or "high" likelihood of them failing.

 

[LagunaGlide]

How deep into the water should my drain lines be under normal operation? Does this affect this issue at all?

 

[Utubereefer]

The height of the overflow and return line is what determines how much water will flow back into your sump.

 

[edd59]

your return should be on or just under the surface with pump running. i wouldnt trust a check valve i dont think there is any need for them. you can drill a vacuum break in the return. google it

 

[Utubereefer]

Check valves are not 100% but I’d rather have it than not. I don’t understand why you wouldn’t put one on

 

[Tangdora]

Should also drill small hole in your return lines facing downward into the water on the stretch of pipe that hanged over the water surface. to help break a reverse siphon. They should be above the water level. start small and slowly increase till you find he ideal size. Be sure o clean the holes out regularly.

 

[JayM]

Drill a small (1/8") hole in your return nozzles near the bulkhead and orient the hole so that they're just about horizontal with the water surface. Water will stop siphoning when the level gets to the holes.

 

[Tommy B]

https://gmacreef.com/category/plumbing/

This helped me a lot when I got my first sump system.

 

[Utubereefer]

Drilling holes in the return line means it’s going to push water out of those holes when your pump is running. That seems silly. Your pump is going to be on more than off. Just install a check valve. You have a ton of space for one.

 

[JayM]

Drilling holes in the return line means it’s going to push water out of those holes when your pump is running. That seems silly. Your pump is going to be on more than off. Just install a check valve. You have a ton of space for one.

Why does it seem silly? It’s free, it works, has no negative effect on pump operation or flow and at most, takes 5 seconds of maintenance a few times a year.

 

[Utubereefer]

Why does it seem silly? It’s free, it works, has no negative effect on pump operation or flow and at most, takes 5 seconds of maintenance a few times a year.

How does it not cut down on the flow rate of your return pump?

 

[exnisstech]

Drilling holes in the return line means it’s going to push water out of those holes when your pump is running. That seems silly. Your pump is going to be on more than off. Just install a check valve. You have a ton of space for one.

There's nothing silly about a syphon break. It is silly to depend on a check valve to prevent a flood IMO .
The only thing a check valve is good for is to prevent a bunch of air from blowing back out when the pump it turned back on, again JMO
If the sump is overflowing when the return is off and you have already added syphon breaks then the sump is too small or its over filled.

 

[exnisstech]

How does it not cut down on the flow rate of your return pump?

The hole is too small to have any noticeable effect. If your pump can't handle an 1/8" hole in the return line the pump needs upgraded.

EDIT: rare occurrence or not they will and do fail so why risk it? IME everything mechanical/ electrical will fail. The only question is will the failure be catastrophic or a minor inconvenience?

 

[Utubereefer]

The hole is too small to have any noticeable effect. If your pump can't handle an 1/8" hole in the return line the pump needs upgraded.

If you have a check valve it’s not needed in my opinion. But you guys do your thing.

 

[edd59]

How does it not cut down on the flow rate of your return pump?

unless your using your return in a closed loop its just returning water ot the display. 1/8-1/4 will not be noticable. its pretty much fool proof unless a snail blocks the hole but if your returns are high enough its only for redundancy.