Finally!!!
Hi;
I'm curious with the above set up?
You have a variable flow-rate return pump & a gravity fed ATO maintaining the level in that part of your sump.
If the pump is running at half speed, & you ramp it up, the water level in that part of the sump will fall significantly & level back up with an influx of RODI water via the ATO.
How do you get around this?
Do you have the pump running at full throttle permanently?
or, you don't change the setting?
or....?