[Auto water changes question]

20 hours ago, Cory said:

I believe you're confusing an RO/DI unit with what I use, which is a carbon block filter, to just remove chlorine and other low level contaminants. 

Ahhh, I get it now thanks ! I thought the two were the same, thanks a lot Cory ! 

[Auto water changes question]

Hello everybody,

I've watched Cory's video on the automatic water change system and there's one thing I can't figure out. There's a filter that the water goes through to remove chlorine and other polluants but doesn't it also remove Hydrogen ions and minerals making pure water ? How can it go directly to the aquariums if this water has no buffer or minerals ? Are they added in another way ? 

Thank you for any answers