A Rena XP2 is what I would put on there. I have three XP3s on my larger tanks and you have to put your ear physically on them to even tell they're on.
Is your tank getting a lot of direct sunlight? You must be getting a ton of evaporation to even be able to top it off every day.
Is your tank getting a lot of direct sunlight? You must be getting a ton of evaporation to even be able to top it off every day.