Sump Help

[Shep]

Ok, so I recently installed a sump and everything was fine until yesterday. Long story short, every few hours my overflow makes a crap ton of noise and then the level in my sump raises by about half an inch, then it slowly lowers again. The only thing I changed was I drilled a hole in the return at the water level to break the siphon if the power goes out. Any suggestions? There isn't a flood risk but it makes it impossible to use an ATO.

Overflow: Deluxe CS50 with Lid and Aqua Lifter (300 GPH)
Return pump: Sicce Syncra Silent 1.5 Pump (357 GPH)
Sump is about 4ft below the tank

 

[AllSignsPointToFish]

My sump goes though some cycling like that as well, although I'm not sure my sump level changes.

What does the level in the overflow box do? If that stays constant, can you place your level switch in the overflow box instead?

 

[Shep]

I'll put a mark on the side to see what happens, have not seen if it does change.

 

[kschweer]

Can you take a picture of the plumbing? Any dips in the drain line?

 

[TheEngineer]

Sounds to me like an intermittent siphon.

 

[AllSignsPointToFish]

I'll put a mark on the side to see what happens, have not seen if it does change.

Another thing I noticed is that when I run my flexible drain lines into filter socks, this behavior seems to go away or at least be significantly abated. FYI.

 

[TheEngineer]

When in the filter sock, does the line stay out the water? Is it under water when not in the filter sock?

 

[AllSignsPointToFish]

When in the filter sock, does the line stay out the water? Is it under water when not in the filter sock?

I haven't looked, but I believe the line is under the water while in the filter sock. I have no reason to believe otherwise.

 

[TheEngineer]

Oh wait, I just realized you aren't the OP.... don't want to derail from @Shep's question. Start another thread and let's discuss there.

 

[Shep]

Can you take a picture of the plumbing? Any dips in the drain line?

I'll take some pics right now, but until then I have a 1.25in ID tube that runs down from the overflow where it connects to a 1in ID tube that then empties into the sump through a piece of 1in ID PVC. The return line is 3/4in ID tubing and no drips in any lines.

Sounds to me like an intermittent siphon.

Anyway to prevent this?

 

[Shep]

Here you go

 

[TheEngineer]

I don't think this has anything to do with the hole you drilled in the return line. When this happens, what is going on in the overflow box? Does it eventually drain enough to start sucking in air on the side outside of the tank?

 

[kschweer]

Here you go

I would say that it may have to do with reducing from the 1.25" to the 1". It may be just enough to back things up enough that periodically you get a siphon on the drain. Causing it to drain faster than normal.

 

[Shep]

Darn, well that sucks.

 

[TheEngineer]

Does the drain line in the sump sit under water or in the air? You may just need a valve to control the drain rate.

 

[kschweer]

Is there a bulkhead on the sump? If
You can I would drill a bigger hole for an 1.25" bulkhead and run 1.25" hose all the way to the sump.

 

[Shep]

Does the drain line in the sump sit under water or in the air? You may just need a valve to control the drain rate.

Its underwater

Is there a bulkhead on the sump? If
You can I would drill a bigger hole for an 1.25" bulkhead and run 1.25" hose all the way to the sump.

The sump is an acrylic tank so I do not know if I can really drill it.

 

[TheEngineer]

Its underwater

OK. I'm thinking this is an intermittent siphon problem more and more. I don't have experience with reductions in line size causing siphons, but sounds like @kschweer does. When you hear the loud noise in your sump, does it sound like air bubbles?

 

[Shep]

OK. I'm thinking this is an intermittent siphon problem more and more. I don't have experience with reductions in line size causing siphons, but sounds like @kschweer does. When you hear the loud noise in your sump, does it sound like air bubbles?

I would say it does sound similar to air bubbles

 

[Jimbo662]

How far below the water does your drain line end? If it's too far down you may be trapping air in it.