How to raise the pH value in aquarium water
The pH value of water has different values in water bodies all over the world. Fish live and breed in a narrow pH range. Some fish prefer low pH levels, some prefer neutral pH levels and some fish need water with high pH levels. If the fish require water with a high pH value, e.g. cichlids from Lake Tanganyika, you should know how to raise the pH value.
First of all, test the tap water for the pH value. This can be done with a pH-measurement kit, which can be purchased at a pet shop.
If the pH of the tap water is higher than that of the aquarium, simply change some of the water with fresh water to raise the pH in the aquarium. Please note that the biological processes occurring in the aquarium acidify the water, so the pH value will usually drop over time. This process must be monitored, as the fish living in water with a high pH, too low levels of acidity can be fatal in such water, even the biological filter stops working.
Aquariums that have not been subject to water changes for a long time may have dangerously low pH levels, therefore the pH value should be permanently monitored and increased if necessary.
There is a special agent, API pH UP, available on the market to gradually raise the pH level in freshwater aquariums without harming all the inhabitants. It is a very quick and easy way to raise the pH in your aquarium. Add it to the water according to the instructions and then check the acidity reading. Do not raise the pH by more than 0.5 per day and do not exceed a pH of 8.5, as even hard water, and fish that require high levels of acidity do not need it to be above this value.
Another easy way to raise and maintain the pH is to use coral sand and aragonite containing lime as substrate. When the pH is less than 8.2, they dissolve over time, releasing pH and KH buffers, calcium and magnesium. Coral sand can be added to aquariums with soft water, where the pH value continues to decrease. Adding enough coral sand can raise the pH to 8.2. There will be no further rise in acidity, so the aquarium fish will not suffer any discomfort.
Lower the CO2 level in the water
Carbon dioxide (CO2) lowers the pH value of the water and the water needs to be aerated more vigorously to raise the pH value.