Randy Holmes-Farley
Reef Chemist
View BadgesStaff member
Super Moderator
Excellence Award
Expert Contributor
Article Contributor
R2R Research
My Tank Thread
- Joined
- Sep 5, 2014
- Messages
- 67,346
- Reaction score
- 63,689
I took a gallon of my RODI water mixed with salt and tested it. The level in my fresh saltwater was .26, where my tank is at .07 and rising. Unless the phosphates were coming from the salt, which I don't think is possible, but I may be wrong. I guess it might not be the main source, but it is definitely a source.
Mike
Definitely not the main source when used as top off, and possibly not even worthy of thinking about, but a new DI or a second DI will lower it.
I'd equate it to worrying about heat loss from drafts around an old window, when the window next to it is actually open.