Carbon causing pH spike and cloudy?

PedroYoung · May 11, 2018

I haven't used carbon in my tank in a couple years. I've been having a slight cyano outbreak so took the carbon reactor I've been using in my live rock bin, rinsed it out and reloaded with ROx carbon from BRS and a small amount of GFO. When I fired it up i noticed a spike in pH (about 0.1, from 8.3 to 8.4) and several hours later I noticed the display tank water was a little cloudy. I killed the reactor, but trying to figure out what might be going on. Anyone have any insight?
Edit: I did rinse the carbon/GFO by running about 2.5 gallons through the reactor into a bucket prior to running in the sump

LCC · May 12, 2018

I have never had carbon or gfo cause cloudy water. Carbon usually helps to clear the water nor have i noticed a spike in ph. Im not a chemist but i dont think either of those products would cause a ph spike.

Randy Holmes-Farley · May 12, 2018

GAC doesn't typically cause a pH change.

Some brands of GFO may be surface treated before you get it. A popular way to regenerate it, for example, involves a high pH rinse. Maybe it had excess high pH residue on it.

Might also have been unrelated.

PedroYoung · May 12, 2018

Randy Holmes-Farley said:
GAC doesn't typically cause a pH change.

Some brands of GFO may be surface treated before you get it. A popular way to regenerate it, for example, involves a high pH rinse. Maybe it had excess high pH residue on it.

Might also have been unrelated.

My guess is that the exhaust from the reactor was stirring up sediment in the sump causing the cloudiness and the pH rise might just have been the normal daily rise, just masked because the sump was not being refreshed from the display while I was installing the reactor. I'm firing it up again today, being more careful with the outlet and see what happens.