RODI not removing ammonia

[Randy Holmes-Farley]

Just dropping bimbs here....

Once upon a time i was told that chloramine evaporate from water quickly, that was always method of preparing fw water, just leave it in open vessel for few hours = no chlorine in water......

Not true. Works for chlorine, but not chloramine.

 

[Randy Holmes-Farley]

Ok but doesn't the mixed bed have cation resin in it? Why wouldn't that lower the Ph?

All of these sorts of questions are answered in detail here:

Reverse Osmosis/Deionization Systems to Purify Tap Water for Reef Aquaria by Randy Holmes-Farley - Reefkeeping.com

 

[Randy Holmes-Farley]

The DI filter is new, only about a month or two old.

Are you measuring tds of the effluent?

 

[Randy Holmes-Farley]

I would assume becuase is doing 2 processes at the same time so it won't lower the ph.

It lowers and raises the pH just like a single resin bed, but the change is confined to the bead interior. So it works out fine.