Light impacting PH?

[friendlyAlien]

Yesterday, I did some organizing of my wiring around the aquarium and accidentally unplugged the light controller. Unfortunately, when that happens, the Phillips lights default to 100% on, and so my reef enjoyed 6 hours of 100% LED light intensity before I noticed it. I usually run it at 55%.

The way I caught it was watching my PH to rise fairly rapidly (not absolute, but relatively).

once I caught it the PH is falling again steadily and I expect it to go back up once the lights are back on.

That made me curious. How does the light impact PH? The only thing I could come up with is photo synthesis from the corals / algae but then I would have expected ORP to go up too and it stayed steady ...

Any explanation why the light impacted the PH in such an interesting way?

 

[JaaxReef]

I’m not a scientist, but higher light may allow for stronger photosynthesis of algae, corals, and other organisms, and therefore a reduction in co2 which can have an impact on, or raise, PH.

I think most people’s PH is highest during peak lighting hours.

 

[rishma]

Yep, you got it. Photosynthesis. It’s typical to see higher pH when light intensity is increased. More CO2 is consumed and the pH goes up.

 

[Randy Holmes-Farley Verified Community Expert]

The others are certainly correct, but just as a joke for regular readers, did you have pancakes for breakfast?

If so, you should call this the pancake method for raising pH, and have pancakes every day to ensure it stays up. Lol

 

[friendlyAlien]

That is a more significant impact than I would have thought for just photosynthesis. And, of course, now I wonder whether I should increase the intensity to chase that perfect number. What could go wrong!


Time to start a youtube channel to promote par based PH control for your reef tank :-)

 

[Randy Holmes-Farley Verified Community Expert]

That is a more significant impact than I would have thought for just photosynthesis. And, of course, now I wonder whether I should increase the intensity to chase that perfect number. What could go wrong!


Time to start a youtube channel to promote par based PH control for your reef tank :)

The entire day/night pH change in reef tanks is due to photosynthesis. :)