Keep in mind that even after your aquarium has established a balanced cycle, things can happen that cause spikes in ammonia. Adding a number of new fish, the death of a fish, use of medications to treat disease, and even rigorous cleaning of the filter or substrate can all disrupt the biological colonies enough to result in an ammonia spike. Therefore, it's wise to include ammonia testing in your monthly maintenance routine.
Video - How to Test for Ammonia in Freshwater Aquariums
Owners Ammonia Stories
Like ammonia, nitrites will rise if something disrupts the establish biological colonies in the aquarium. A number of the medications used to treat fish diseases affect the biologicals, so monitor nitrites closely when using any medications or new chemicals in the tank. Anytime the ammonia rises, it's almost a given that the nitrite will soon rise as well.
Video - How to Test for Nitrites in Freshwater Aquariums
Owners Nitrite Stories
Among the negative effects are the reproductive ability of adults and growth rates of young fish. It is felt that nitrates can compromise the immune system of the fish, leaving them more susceptible to disease than fish that are not subjected to high levels of nitrates. Further, conditions that increase nitrates often decrease saturated oxygen, which is dangerous for your fish. Last, but not least, elevated nitrates will contribute to algae overgrowth.
Good tank maintenance, water changes, and the use of special filter media will help keep nitrate levels low. Nitrate testing should be done monthly as part of regular maintenance.
Video - How to Test for Nitrates in Freshwater Aquariums
Nitrates in the Aquarium
Video - How to Test for Phosphates in Freshwater Aquariums
Phosphates in the Aquarium
Some fish are tolerant of a wide range of pH levels, while others highly sensitive to the pH levels, particularly when spawning. In those cases, it's wise to ensure that you are able to provide the proper water conditions on an ongoing basis. Various means are available to maintain either an acid or alkaline pH. Regardless of methods employed, testing regularly and keeping a record is key to success.
Video - How to Track and Manage Aquarium pH Levels
Video - Normal pH Levels for Fish
Do Rocks Affect the Water pH?
Matching pH of Aquarium Water