GFO or carbon lower ph?

[Fishfinder]

my ph is consistent around 7.8 in the morning getting up to about 8.0 in the afternoon. Last night i started running some GFO and carbon in a reactor. This morning my ph is 7.6. I've never seen it that low. Is that an effect of the GFO and GAC?

 

[Randy Holmes-Farley Verified Community Expert]

Depending on how the GFO is prepared, it may have a temporary impact on pH, and may alter the demand for alkalinity.

 

[Fishfinder]

Weird because my alk went up slightly also

 

[Randy Holmes-Farley Verified Community Expert]

Weird because my alk went up slightly also

One or the other is likely test error or an addition difference. Calcium cannot singificantly be removed without alk dropping.

 

[Tariq]

I always suspected the GFO was responsible for my pH drop back in the day.
I have not used GFO in years and don't miss it a bit.

 

[Fishfinder]

I just shut it off