reverse osmosis

[amstar15]

if you are just topping off water say a gallon to or two do you need to add any additives to it? or only when you are doing bigger water changes?

 

[Salt Freak]

I dont and a lot of these guys have RO top off installed on there tank which it will automatically top off the tank as it evaporates. and they dont additives add them. see only the water evaporates.

 

[parker313]

Ditto. I also use just plain R/O water for my top offs.

 

[RamJet]

Same here, no need to add at the time of top off.