GFO question

[bundy13]

I am posting this here because my water parameters should be close to what others are running on this forum,

I decided to start keeping SPS corals about 6 months ago
so i go really got serious about keeping my po4 low ,
i am using phosban in the phosban reactor,i purchased a hanna photometer to get more accurate results

thing is my phosban keeps turning a grey color after about a week of using it,i am using 150 grams in a 150 gallon system ,i only have 3 fish and i feed once a day and lightly
i have a deltec 701 ratted for up to 450 gallons,
My Hanna gives me a reading of PO4 of 0.02,when i start the GFO
but afer about a week of use it starts to turn grey and my readings on my hanna start to go up a little nothing drastic 0.05-0.06,so i change it and they go down to normal 0.02 for my tank

i emailed two little fishies,and they said that my ca.and alk, were causing it to turn grey,
but i have normal SPS water parameters,i am using CA. reactor
and i am dripping lime to help keep ph. up from the CA. reacor making it drop any one else have this happen when using phosban-im going to go broke replacing it once a week thanks

CA 430-440
ALK-9-10 DKH
MG-1350-1400
PH 8.1-8.0
NO3-2
PO4 0.02


thanks

[Jefe12234]

Is your limewater dripping in front of the phosban reactor? The high pH could be causing some precipitation. I know when I was dripping a lot of limewater my sandbed would clump. You have the calcium reactor to counteract it, but maybe it's not enough or you have a locally high pH near your phosban reactor.

[MACH5]

This happens to me as well. Only the upper layer does this. In my case it starts turning grey after about 3 weeks. I'm not so sure that this actually it's an indicator of its effectiveness.

[bundy13]

Jefe12234 ,at first i was dripping the CA. reactor affluent,and the kalk in my sump before the phosban reactor,so i figured id move the phos.reactor and that would take care of that but no matter were i put the reactor i tried it in an overflow ,in my return compartment,in the main display,it turns grey on me,

MACH5 i wish mine lasted 3 week, and the bad thing is that it does seem to loose its effectiveness when it changes as my po4 starts to slowly climb according to my Hanna

any thoughts ,are there others running phosban with close to these water parameters

CA 430-440
ALK-9-10 DKH
MG-1350-1400
PH 8.1-8.0
NO3-2
PO4 0.02

or maybe another GFO Product? thanks