water evaporation

[sSjey]

For topping up, you're essentially replacing water that's already been purified by evaporation. So, using a pure source of water like RO makes sense. Since the RO process removes chlorine and chloramine, there's no need to add dechlorinator.

[sSjey]

I'm not familiar with RO water, so I'm not sure about its shelf life. I'd imagine though, if stored for a prolonged period, it might be susceptible to contamination since there's no chlorine to prevent bacterial growth.

[MommiePie]

If topping up is preferred, consider using distilled or demineralized water as an alternative to tap water, since it doesn't contain minerals that can accumulate in the tank over time.

Thanks for the info, I'll keep that in mind