What Are the Causes of an Unbalanced pH in an Aquarium?

Proper water chemistry in your aquarium can make or break the health of your fish. One of the most critical measures of water quality is pH, which indicates the acidity or alkalinity within the tank. The pH scale ranges from 1 to 14, with the numbers 1 to 6 being more acidic and the numbers 8 to 14 being more alkaline. Several different factors can cause unbalanced pH in an aquarium tank.

  1. Changes in pH

    • In general, fish can tolerate a wide pH range, according to the The First Tank Guide website. However, if you are breeding fish, the pH can have a bearing on their ability to spawn. Though it̵7;s not necessary to worry constantly about the pH level of the tank, be aware that any change you make to the aquarium environment can cause a change in the pH level. Testing after changing water or adding components to the tank is generally sufficient.

    Water Changes

    • The water itself can have an effect on the pH level. Many communities use water that comes from limestone aquifers that dissolve lime into the water. Though some lime may not be a problem, too much can cause the pH to rise to unhealthy levels. When you transfer this water to the tank, the pH of the water is raised. Plumbing can also cause pH levels in water to rise. To find out the natural pH of your water, fill a bucket and test it with pH test paper, then allow the water to sit a while and test again. If the pH is high, you will have to adjust the aquarium water each time you add water.

    Buffers

    • Water that is able to keep the conditions within the tank from changing the pH is said to have buffering capability. Buffers are carbonates and bicarbonates in the water that help to stabilize the acids that are formed. These chemicals act like sponges to soak up the acids. Some types of water do not have good buffering capability, causing the pH of the water to vary.

    Decorations

    • Keep in mind that decorations you put into the aquarium may be made from materials that can change the water̵7;s pH. Decorative castles, caves and sea shells can consist of calcium carbonate, which is an alkaline substance that raises pH. You may have to remove these items to keep the pH level in your tank stable.

    Other Causes

    • Many things ordinarily found in aquariums can have an effect on the pH level, including coral skeletons, dead plants, pieces of wood, peat or limestone. Remove these objects to see if the pH level returns to a normal range before attempting to adjust the level with chemicals.

      Determine the composition of your gravel. Some gravel is made for salt water tanks, which generally need a higher pH. Chemicals used to remove calcium carbonate from the water can add too much carbon dioxide, which also causes changed in pH. Even indoor air that has a high concentration of carbon dioxide can affect the pH of your tank.