Tank water level and automatic top off systems

[jreising15]

Wondering if anyone can explain why the return chamber of the sump is the only chamber affected by evaporation. This is where the ATO level probe goes and where top off water is added. I have a Red Sea tank with a separate return chamber from the rest of the sump.

I'm getting ready to do my initial fill and I can't quite figure this out. Thanks.

 

[moretor1]

Wondering if anyone can explain why the return chamber of the sump is the only chamber affected by evaporation. This is where the ATO level probe goes and where top off water is added. I have a Red Sea tank with a separate return chamber from the rest of the sump.

I'm getting ready to do my initial fill and I can't quite figure this out. Thanks.

The return pump chamber water level is the first one to drop, a tiny drop in tank level can make the pump empty faster than it can fill

My tank would do that and shoot bubbles fairly often and I realized I just need to keep the water level higher

 

[RocketEngineer]

All other chambers have a downstream baffle that prevents flow until that chamber is full. It’s only the last one that doesn’t have a baffle controlling the water height in it.