Tunze 3152 constant drip?

[AdamNC]

Just noticed today my ATO is dripping about 1 drop of RO per second. The RO bucket is about 3 feet below the fill tube exit. Could the pump have gone defective? It still fills like normal but just doesn't stop dripping. I've already unplugged/plugged back in the metering pump and turned it upside down to make sure no air is trapped inside.

 

[RareEarthCorals]

The pump is on or off there is no in between. You could have some siphoning causing a drip which would be strange with your pump three feet below the fill tube. I would unhook the tube to break any siphoning, make sure you have only what you need in tubing between the fill tube and your pump. If you have excess dropping below your bucket before going up to your tank you could have a siphoning going on.

 

[AdamNC]

Found it, thanks REC. I think there was a small air bubble in the feeder tube. I unhooked it, blew the excess water through the tube, hooked it back up and all is normal again.