multi water level channel 2 issues

[Ademster]

Channel two of my multi water level expansion doesn't hold its calibration. this is in my ato container... I use it to control a solenoid valve to turn on and off my rodi. it keeps dropping. My water level in the ato is 90% reef angel sees it as 68% which obviously is correct. I have calibrated it 5 times and it still drops.

any ideas?

channel 1 which is in my sump is accurate

[rimai]

It's leaking air somewhere.

[WIReefer83]

I have a similar issue, but it leaks air over a few weeks. How are people fixing this? Silicone around the tube where it enters the orange cap? Hose clamp around the tube where it connects to the multi-level RA expansion?

[Ismaclst]

I used PVC glue around the 1/4" tube and a layer around the other joints for safe measure.