2 gallons a day evaporation? Is this right?

[greetl01]

When I moved my power heads a little lower from the surface it decreased by half. I only have a 20 gallon though

 

[Greg P]

I too go through between 1 and 2 gallons of RO topoff daily depending on the outside temps/furnace on/ac on
I have 115g total

If you're happy with the running level of your system after 24+hrs I'd say the system is stable enough to install the ATO and then keep monitoring it.