What causes low pH?
There are two main causes of low pH in the reef aquarium: • The breakdown of waste organic material leads to acidification. • Insufficient water movement can be a cause of low pH readings. If there’s not enough disturbance at the surface of the aquarium CO2 levels can build up in the water, depressing its pH. By increasing surface water movement, the excess CO2 will be gassed off, returning the pH to normal.
