top off water question.

[sansouci01]

I bought a ATO system for my 20 gallon tank. Works great. Keeps the water level perfect. My question is, I only use a few ounces of water a day to keep it topped off. I have a 2 gallon container of ro water next to the tank for top off. How long will the water stay fresh? Should I change the ro water once in a while or will it last a long time. I don't want the water to start growing stuff in it if that's possible.

 

[z_dano]

If it's ro you'll be fine as long as there is a cover on it

Sent from my HTCONE using Aquarium Advice mobile app

 

[sansouci01]

Thanks...just checking