What Causes High Acid Water in Freshwater Fish Aquariums?

Aquarium water with a pH level below 7.0 is acidic and above 7.0 is alkaline. Some species of cichlids thrive in acidic water, but you must regularly monitor pH levels with a test kit to ensure acid levels remain stable. Acidity levels in your aquarium water can elevate if you add something new to the environment or a biological problem develops within your tank.

  1. Fish Waste and Overfeeding

    • Fish waste is highly acidic, and too much uneaten food in your aquarium adds to the problem. Overfeeding is bad for your fish, and decaying matter leads to poor water conditions and an increase in acidity. Use a gravel cleaner to remove excess waste from the bottom of your tank and feed fish sparingly.

    Unnecessary Use of Chemicals

    • High acid levels are often a result of a fish-keeper's inexperienced but well-meaning intervention with pH modifiers. Altering the water pH level in a fish tank sounds easy when you see a shelf full of products at the pet store claiming to do the job for you. Commercial pH stabilizers create chemically elevated acid or alkaline water conditions, but if other factors are introduced, the levels can spike out of control. A new fish, your hand or even a tank ornament are all it takes to alter pH levels in treated fish tank water. Start over with fresh, dechlorinated water to quickly re-establish a safe environment.

    Water Softness

    • Fish tank water comes from your domestic water supply, and if you live in a soft water area, your fish have a naturally acidic environment. Do not use driftwood in soft water because it lowers pH and increases acidity levels. Add crushed coral, rocks or a few seashells to your aquarium to raise pH and create a more pH neutral environment.

    Remedies

    • Remove the cause of high acid levels in your aquarium, and maintain good water quality with frequent partial water changes. Monitor your tank with regular pH tests to catch any problems at an early stage.