Overflow Box Water Fluctuation Help!

[piranhaman00]

Hi all,

I have a herbie style overflow set up using the Eshopps eclipse S. The images are just to show water level.

I have the water level perfect, right at the emergency drain pipe, its dead silent, just like this image.

Well last night my high water level sensor went off. I went out to investigate and saw the sump water level was high, causing the float switch to trip. I figured the tunze water level sensor failed, I unplugged it and went to bed. In the morning, the water level was back to normal, which was odd as it should not have evaporated that quickly but didnt think much. I cleaned the sensor and was getting ready for work and the high alarm tripped again! I couldnt figure out what was wrong, I looked at the overflow box and the water level was here, see image.

Somehow, less water was getting to DT, or more water was getting to sump. The water level in overflow went down to main drain, but then slowly rose back up to where it normally is. So whatever is causing this, is periodic. Something didnt completely fail.

In my mind two possible problems:

1. One of the two return pumps is failing on and off, causing less water to reach DT, thus raising sump level.
2. The gate valve is failing (possible?) letting more water to sump than it should.

Is there a different possibility as to why this is happening? I watched the return lines and they both were still shooting water so I dont think it is that, and I dont think a gate valve can fail? Not sure. Ideas please!

 

[Doctorgori]

You got a skimmer in your sump? And what total volume we talking here? You got the valve adjusted for silence? Snails? How many overflows? 2 returns pumps you say?
Did you use that jacked up template that comes with Eshopps overflows? (IMO the template has the water level waaaay too low)
Following...

 

[OoNickoC]

The water level should be where you indicated with the black lines in the second pic no?

 

[piranhaman00]

You got a skimmer in your sump? And what total volume we talking here? You got the valve adjusted for silence? Snails? How many overflows? 2 returns pumps you say?
Did you use that jacked up template that comes with Eshopps overflows? (IMO the template has the water level waaaay too low)
Following...

40 gallon display with a 29 gallon sump, 60 gallons total volume. One central overflow, used their template, put on inside as far as could with trim. The water level is right below trim line, perfect for what I wanted. Dual return pumps each feeding their own return line, one on each side of the overflow box.

The main drain is gate valve adjusted for silence, it has been running for two weeks no issue, dead silent. No adjustments in those two weeks, this happened out of the blue.

Protein skimmer in sump, adjusted and running for past week or so. Skimmer should not have an effect on the water level in box though?

Some snails came over with live rock, but I have seen 4 maybe so I dont think thats it.

The water level should be where you indicated with the black lines in the second pic no?

Water level should be at first picture, right at the top. This results in dead silent operation.