how much water does a 30 gallon evaporates daily?

[reefy]

Hi folk, I am wondering if anyone is using a dosser pump to ATO(auto top off) to be specific "time topping off" I have a 29 gallon Biocube. I know every system is different, I just needed a roughly guestimate. as for pumps, I am running maxi 1200 for returm and aqualife 115 Skimmer. no powerhead yet, will be adding an Jebao rw-4. any input will be greatly appreciated.