Why does the presence of light affect PH ???
- Thread starter REEFKEEPA
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rigleautomotive
Premium Member
algae and corals consume CO2 and aspirate O2 and the less CO2 you have the higher the ph.
McTeague
In Memoriam
Saltwater has a pH of around 8.0 to 8.3, and has a significant intrinsic buffering capacity. However CO2 and other metabolic byproducts from the aquarium inhabitants will tend to reduce the pH.
This will to some extent be resisted by the normal buffering mechanisms but these can be exhausted allowing a rapid fall in pH. In tanks with a heavy algal growth, during the period of illumination the opposite may occur where all the available CO2 is utilized; bicarbonates are then used for photosynthesis resulting in the precipitation of carbonates and a rise in pH. This is why it is important to take your PH test at the same time of day/night each time you take a test. Running your sump's refuge area's light on an opposite cycle of the main tank can reduce this PH swing between daytime and night time.
This will to some extent be resisted by the normal buffering mechanisms but these can be exhausted allowing a rapid fall in pH. In tanks with a heavy algal growth, during the period of illumination the opposite may occur where all the available CO2 is utilized; bicarbonates are then used for photosynthesis resulting in the precipitation of carbonates and a rise in pH. This is why it is important to take your PH test at the same time of day/night each time you take a test. Running your sump's refuge area's light on an opposite cycle of the main tank can reduce this PH swing between daytime and night time.
