Phosguard yellow?

alexytman · Oct 13, 2018

My new phosguard just turned yellow. This is my first time using phosguard. The phosphate stopped dropping and it's now yellow. Does it mean it's exhausted?

wesman42 · Oct 13, 2018

Yes, that's the case. Make sure you are following the instructions for using a little amount instead of a large amount because it will bottom your nutrients and quite possibly lead to dinos.

So here's my follow-up question: What were your phosphates when you started with PhosGuard, and what are they now? Having 0 phosphates is asking for trouble.

JumboShrimp · Oct 13, 2018

Agreed— great stuff in a reactor, but use a little cautiously (ease into it). Also, when you see it going from white to yellow (dirty white), the product is getting exhausted.

alexytman · Oct 13, 2018

JumboShrimp said:
Agreed— great stuff in a reactor, but use a little cautiously (ease into it). Also, when you see it going from white to yellow (dirty white), the product is getting exhausted.

My phosphates were plateaued at 0.5 using my Ats. This is bcuz I have two lionfishes and a eel. My phosphates dropped to 0.1 around or slightly lower... I have a dirty tank :(

Randy Holmes-Farley · Oct 13, 2018

Yellow is not caused by phosphate binding to phosguard and does not necessarily indicate exhaustion or not.

Yellow is most likely organics binding to the surface, but might also be metals like iron.

JumboShrimp · Oct 13, 2018

Randy Holmes-Farley said:
Yellow is not caused by phosphate binding to phosguard and does not necessarily indicate exhaustion or not.

Yellow is most likely organics binding to the surface, but might also be metals like iron.

Thank you @Randy Holmes-Farley. I can say “I learned something from a chemist today!”