Nitrate (ppm)

Do not need to worry about nitrates as it relates to fish deaths or direct health. High Nitrate levels may cause some algae growth, but not harmful to fish. Very high nitrates in an old existing aquarium could indicate “poor” overall water quality/conditions, necessitating a water change, but the nitrates themselves are not harmful to the aquarium or fish. It means water changes haven’t been done regularly, so essentials for fish metabolism (proteins, amino acids, vitamins, minerals, etc.) have been depleted (creating poor overall water quality) and need to be replaced for fish health --- the best way---partial water changes!

Using products to reduce nitrates does not help the poor water conditions that exist; it won’t replace the vital nutrients (proteins, amino acids, vitamins, minerals, etc.) that are needed for the fish.

pH (ppm)

Fish can tolerate a wide range of pH, no need to adjust unless trying to do specialized spawning/breeding.

Only a significant fluctuation/swing in pH can be problematic for fish—this can only be shown or deduced by having at least 2 tests (a baseline for reference), otherwise the first single test is meaningless without another test to compare it against.

Total Alkalinity Buffering Capacity (ppm)

Is the waters ability to absorb acids (caused by de-nitrification, respiration, etc.) to prevent a sudden change in pH. Probably the best test for any customer/aquarist to do on an aquarium. Requires multiple tests (need a history), not just one. Test regularly and when it drops, that indicates it’s time to do a water change, which will buffer and stabilize the pH and replenish all of those valuable essentials the fish need for bodily functions.

Total Hardness (ppm)

Not a real concern. Many, many years ago, when most fish available for aquariums came from their natural environment, hardness may have played a role. Today, not any more, as most aquarium fish are raised (aqua cultured) in ponds or aquariums and accept a wide range of hardness. Hardness may play a factor for certain spawning or breeding purposes, but not everyday aquarium keeping.