Sump level fluctuation driving me nuts!!

[Marco_99]

But how you have your UV it looks like air or water could push back into where you have your ball valve shut off ( lock air in there?) Idk I’ve never hooked up a UV but that’s a pretty big backchannel of pipe that depending upon how air or water reacts pushing or sucking inside there??

 

[Charley75]

Just to clarify when say “cycle” I mean like every 20 min or so the level on the overflow box drops for like 5 or so and I get the water fall sound, and then it rises back up and quiets down. And course each time it drops, the return section in my sump rises and sets off my ATO alarm.

 

[Charley75]

May even be more often that. My drain lines are 1.5” so I know they can handle the flow. Even with the return (Varios 8) turned way down it still does it.

 

[Marco_99]

May even be more often that. My drain lines are 1.5” so I know they can handle the flow. Even with the return (Varios 8) turned way down it still does it.

A lot of people say an inch or less. I know I had to keep cutting mine because it would take the overflow box to get enough water to break the pressure in my sump. It causes it to surge just like you’re saying.

Your return line with that pipe back channeling above your UV might be getting air in it and the return flow might be trying to pull a siphon from that part of the pipe and drawing air or an uneven flow of water. The reason I say that is because the flow is going to least resistance (your tank) and whatever is in that part of the pipe is going to get siphoned out and going with the flow and might create an air pocket or erratic pump flow, maybe. I might try cracking that ball valve just a tid bit so it can pull a tad of water through (like cracking a bleeder valve). You lose nothing to try.

You can also try adjusting your gate valve down very slowly to build a bit more water in the overflow, maybe it needs a bit more on top to hold siphon.

It’s one of these 3 things I would think lol
But personally my surging problem was pipe length into sump. Yeah it can be that fussy

 

[Marco_99]

Look at how high your water level coming in. I would think it should be a nice almost level flow going overtop into your sock box.

 

[UncommonSense]

Look at how high your water level coming in. I would think it should be a nice almost level flow going overtop into your sock box.

The weir there is only 4” wide, maybe less… at the flow rate OP is pushing, this much water packing up behind this short of a weir is very normal…

 

[JumboShrimp]

Whenever I adjust my gate valve(s) to strike an harmonious equilibrium between my overflow box level and my sump level, I only make micro-adjustments. Maybe a 1/64th turn of a gate valve, and then I come back in 3 or 4 hours and gauge the results. Once 'patiently' dialed in properly, I find that I almost NEVER have to worry about it again.

 

[Charley75]

I ran the same drain type for 5 yrs on my tank that I just upgraded from so I’m very familiar with the adjustments needed. That’s the weird thing…pretty much did everything the same as far as plumbing goes. I think the drain lines in my last tank actually extended down further under water. I guess that’s why I’m stumped.

 

[JumboShrimp]

Given that, could you temporarily test a longer pipe (extending further under the water) by adding (but not gluing) one or more pvc coupler(s)/more pipe?

 

[UncommonSense]

Given that, could you temporarily test a longer pipe (extending further under the water) by adding (but not gluing) one or more pvc coupler(s)/more pipe?

I prefer leaving the coupler as the end of the submerged pipe; the larger diameter of the fitting socket seems to help a bit!

 

[JumboShrimp]

Let us know if you solve the problem with trial and error. Wishing you the best!

 

[Charley75]

Much appreciated. I’ll see if I can extend it tomorrow. Will be fun getting to. Not sure how much it matters, but the sump is an Emerald 39. The drain inputs were originally 1”, but I drilled them out to 1.5”. That little drain section is pretty cramped.

 

[Ziggy17]

I had a dead snail lodged in my downpipe causing my issue. Drove me nuts for months before I decided to take it all apart and check. Hopefully it’s a simple fix.

 

[Marco_99]

Given that, could you temporarily test a longer pipe (extending further under the water) by adding (but not gluing) one or more pvc coupler(s)/more pipe?

Yeah who knows maybe with that large of drain in that small of sump pocket you need a longer pipe to create more pressure instead, I would think you’d be able to accomplish that with your gate valve idk. You have plenty of options thrown out there from everybody to test. Do let us know

 

[Reefer Brent]

Do you have a spare return pump to test the system with to rule out the pump?

 

[Uncle99]

When I ran into a similar problem like you described, it turned out that my pump was just pushing a tiny tiny tiny more water into the DT then what the overflows allowed out.

The difference was so small it took a few hours to show up.

So I lowered my flow to zero, then moved it up until it just started down the overflow (gates wide open) and stopped.

Everything stabilized after doing that.

 

[Brian Ardolino]

as others have mentioned sounds the syphon is starting and stoping. First thing I would do is slow the pump down. Then I would adjust the gate valve. I think the goal is to balance the amount of water going to the tank to the amount of water draining to your sump.

 

[Charley75]

So I was able to elongate the drain line a bit more underwater. Is it silent?…no. But even if there is a little fluctuation it’s not enough to set off my ATO alarm anymore. I also realized that I had one of my wavemakers basically aimed directly at the outlet of one of the return lines so I also tweaked that a bit. I think the only change in noise I hear now is just from the alternating flow of my XF 350 causing splashing of water into the overflow. I may ajust that a bit too. I THINK….the bigger issue has been fixed by the longer drain line. Thanks for all of the input everyone.