The Tunze ATO started acting up
It has been giving me the 'wet internals' alarm
There's no way it got wet, but I took it apart anyway to ensure there's no moisture inside it. None.
So, I've done 2 things hoping to solve this issue;
First, the ball valve from the chaeto tank was not sensitive enough to get the drain level perfect. It was sucking air intermittently, filling the sump with bubbles.
Possibly those bubbles were upsetting the optics
The ball valve was just replaced with a gate valve
I've gone from this ( blue valve )
To this
The other thing I've done is move a relay away from the Tunze Controller, just in case an electrical or magnetic field was the issue
From this
To this
Only time will tell now if it's resolved