Does a larger PH swing mean better lighting efficiency?

[hlaalu]

I’m not a PH chaser, and I don’t dose anything but I thought this was interesting. I replaced my old kessels with a photon v2 and noticed the PH is swinging a bit higher. If I’m not mistaken, this is due to more photosynthesis taking place, driving down co2/raising the PH. Would it be safe to assume the corals are liking their new lights? Would this rise in the PH swing also correlate to more growth? It’s only been a few days to be fair. Is there any research regarding the correlation of the daily PH swing and coral growth or if PH is an indicator of coral response to lighting? I haven’t been able to find anything, but I’m very interested.

 

[Randy Holmes-Farley Verified Community Expert]

If you change nothing else (including alkalintiy, etc.) but lighting and see a bigger pH swing, then yes, it means more photosynthesis (except in unusual circumstances where the CO2 level in the home is varying regularly and causing the change).

But alternatively, between two tanks, a larger pH swing does not mean more photosynthesis, since alk levels and degree of aeration and water volume all contribute a lot to the size of the pH swing.