Water Level Sensor dropping to 0

[MisterTang]

I've noticed the water level sensor on my new Reef Angel seems to be having problems - specifically, it showed a reading of zero, and according to spot checks I'm doing, it gradually dropped over the course of 24 hours from a reading of 40. The water level remains reasonably constant because I'm using my ATO's built-in float switch to control the water level. I reverted to the float switch when I suspected that the reading was inaccurate when I kept getting ATO timeouts but would find the sump overfilled. By pulling the sensor tube out of the water and then putting it back in, it immediately registered 40 again, but is already starting to drop despite the water level appearing to remain constant.


Any ideas on troubleshooting? I specifically switched to the water level sensor because I don't trust float switches, but I've had to revert back to the float switch after less than a day using the sensor

[lnevo]

Did you glue the cap to the tube? It needs to be airtight.

[MisterTang]

Did you glue the cap to the tube? It needs to be airtight.

Thanks! I did glue the PVC cap to the pipe, but I did not glue the clear tubing on either side. I may try to do something there...

[lnevo]

Not sure on gluing the airline.

[MisterTang]

Well, it seemed to slightly work - it's now taking about 48 hours for my water level sensor to drop to zero. Any other ideas?

[lnevo]

Sounds like you have air getting in somewhere

[rimai]

Yeah, sounds like air is getting into the pipe.
Did you use pvc cement all around the adapter/pipe junction.
Do you have bubbles where you placed the pipe?

[MisterTang]

Do you have bubbles where you placed the pipe?

This is possible... I do have some small amount of microbubbles that come off my skimmer, but how could I reasonably ensure there's no bubbles at all in my sump? That doesn't seem possible...

[ReEfnWrX]

Proper skimmer design that outputs no Microbubbles or Proper baffle setup will result in no micro bubbles past skimmer section....

Do you currently have a baffle after your skimmer? If so, you could add a second baffle after it that is raised 1" off the bottom of the sump... Water goes down to get to next section air rises and doesn't pass..

[sabo]

Bubbles will actually keep it reading on the high side. He has an air leak, not extra air getting into it.

[ReEfnWrX]

Bubbles will actually keep it reading on the high side. He has an air leak, not extra air getting into it.

Agreed, I was just responding to his statement that it does not seem possible to avoid bubbles in sump. Since you want to eliminate all bubbles so you don't have micro bubbles getting sent to your DT

[sabo]

When I used to go gas work, we used soapy water to find the leaks. Mistertang, you could try that. Take it out of your sump and put it in a bucket of water, then spray soapy water on the joints. Seeing as it takes 48 hours to leak out, they will be very tiny bubbles, but you should be able to see them after a while.

[MisterTang]

When I used to go gas work, we used soapy water to find the leaks. Mistertang, you could try that. Take it out of your sump and put it in a bucket of water, then spray soapy water on the joints. Seeing as it takes 48 hours to leak out, they will be very tiny bubbles, but you should be able to see them after a while.

This is the last thing I will try before abandoning the unit.

I have tried a variety of fixes, including different PVC pipes of differing heights, reconnecting the joints, and placing the sensor in different places/heights in my tank. All I have managed to do is to increase the amount of time it takes to drop to zero by a factor of hours.

[MisterTang]

Good news! I think I may have finally fixed the issue, and am documenting it here for posterity.

The orange insert on the PVC cap apparently was not as tight as it should be - I sealed it with superglue and have had a consistent reading for the last couple of days. Unfortunately, the soap idea didn't seem to work because there just wasn't enough leakage occurring, so it was literally a process of gluing/sealing every connection on the unit. It also explains why switching to a different sized PVC tube or any of my other efforts worked.