Salifert pH Test Kit The pH value in a marine tank has a major impact on the growth of corals and calcareous algae and on If the pH is too low then the cause may be a too low alkalinity and/or a build up of carbon dioxide A low pH can be corrected by improving aeration and by increasing the alkalinity. The Salifert Test Kit is sufficiently accurate to monitor minor pH fluctuations and is scaled from p Sufficient for 50 tests.