JBJ nano ATO question

[punchy7080]

Bought this recently for my 40g breeder with no sump so it’s right in the tank. Still waiting for the low level to trigger and top off the tank. At this point it’s going to add at least two gallons of water back to the high water mark but my understanding is it only does this once to calibrate. My question is, what do I do for water changes? If I unplug so the pump doesn’t run, isn’t it going to recalibrate every time?

 

[Saltyreef]

You want something like this.

XP Aqua Sumpless ATO - Complete Aquarium Auto-Top-Off System for Sumpless Aquariums