High PH in Reef System

[SimonHP]

Dear Thread Contributors.
I have been experiencing stubbornly high pH (8.5) in small scale coral frag runway set up in a cellar. Investigating this issue I read Randy's great article, High pH: Causes & Cures, on ReefKeeping.com (thank you Randy).
I am interested that the subject of atmospheric CO2 depletion in the cellar environment was not raised on this thread as a possible cause of high pH.
Would it be possible that the macro algae and implied high coral load in the system above could utilise CO2 via photosynthesis sufficiently that the atmospheric levels of CO2 drop in the closed space of the cellar environment. No information was given on fish loads in Nickeg79's system. In my system I have very few fish.
Thanks in anticipation of your thoughts,
Simon

 

[ELChingonsReef]

pH up to about 8.6 at least doesn't hurt reef organisms that I've ever seen.

That said, I suspect the measurement is in error since pH rarely gets that high without limewater/kalkwasser.

I know this is an old post but I'm getting 8.6 ph with a co2 scrubber in a 300l tank. It seems like the higher the intensity of the lights the higher the ph goes. Right now it's winter 2022 the house is vacant because everyone is at work at 3pm on a Wednesday. I've never got 8.6 ph in the winter with windows closed in the middle of December. My question is can I get those ph numbers with a co2 scrubber or should I look at recalibration for the apex ph probe?

 

[ELChingonsReef]

I know this is an old post but I'm getting 8.6 ph with a co2 scrubber in a 300l tank. It seems like the higher the intensity of the lights the higher the ph goes. Right now it's winter 2022 the house is vacant because everyone is at work at 3pm on a Wednesday. I've never got 8.6 ph in the winter with windows closed in the middle of December. My question is can I get those ph numbers with a co2 scrubber or should I look at recalibration for the apex ph probe?

 

[Randy Holmes-Farley Verified Community Expert]

I know this is an old post but I'm getting 8.6 ph with a co2 scrubber in a 300l tank. It seems like the higher the intensity of the lights the higher the ph goes. Right now it's winter 2022 the house is vacant because everyone is at work at 3pm on a Wednesday. I've never got 8.6 ph in the winter with windows closed in the middle of December. My question is can I get those ph numbers with a co2 scrubber or should I look at recalibration for the apex ph probe?

In a vacant house and a scrubber and photosynthesis, yes, I can believe the pH is getting up there, but it might also warrant recalibration.

I got close to that in an occupied but leaky old house, no scrubber, and using kalkwasser.

If it really is that high, and if you want it lower, more aeration and keeping alk at the lower end of normal, say pH 7-8 dKH, will drop the pH.

 

[ELChingonsReef]

In a vacant house and a scrubber and photosynthesis, yes, I can believe the pH is getting up there, but it might also warrant recalibration.

I got close to that in an occupied but leaky old house, no scrubber, and using kalkwasser.

If it really is that high, and if you want it lower, more aeration and keeping alk at the lower end of normal, say pH 7-8 dKH, will drop the pH.

Thanks randy. I appreciate your response and all you do for the hobby. I've decided the best course of action is when my apex alerts me the PH is 8.6 I'll just shut the skimmer off. I've herd of some reefers getting up to 9.0 ph with kalc and a scrubber combination. Although I would never do that myself 8.6 as long as it's not harmful to my tank is my limit. The PH didn't get quite that high today. It stayed at 8.5 at its peak this afternoon. I will definitely recalibrate the apex PH probe.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks randy. I appreciate your response and all you do for the hobby. I've decided the best course of action is when my apex alerts me the PH is 8.6 I'll just shut the skimmer off. I've herd of some reefers getting up to 9.0 ph with kalc and a scrubber combination. Although I would never do that myself 8.6 as long as it's not harmful to my tank is my limit. The PH didn't get quite that high today. It stayed at 8.5 at its peak this afternoon. I will definitely recalibrate the apex PH probe.

Thanks! Let us know what you find going forward.