Dirty aquarium water puts undue stress on the fish and can even have fatal consequences. If your pet plans include setting up a fish tank, it’s essential to educate yourself on the freshwater quality. Here, get a head start on your education by learning what constitutes as quality aquarium water.

Essential Fish Tank Parameters

Healthy aquarium water features dissolved minerals, specifically calcium, magnesium, and carbonate. Known as water hardness, the normal magnesium and calcium range for fish tanks is 100 to 250 mg/L.

Carbonate hardness (KH) levels should be between 4.5 and 6.5, with the mineral also helping prevent pH instability. The water’s alkalinity must range between 120 to 300 mg/L since low pH levels increase acidity that can burn fish scales and make them fatally sick.

Other important parameters to remember include the water’s temperature, which should be between 74 to 82 degrees Fahrenheit for tropical fish and between 60 and 75 degrees Fahrenheit for cool water fish. Frequent temperature fluctuations, such as those from tanks near windows that are subject to UV radiation at different times, are stressful for fish and can lower their immunity.

Factors That Lower Aquarium Water Quality

In addition to checking the water temperature daily and taking steps to avoid fluctuations, such as moving the tank away from a drafty door, you need to know about harmful aquarium chemicals. Chlorine and chloramine, for example, are present in city water supplies and can result in chlorine poisoning that kills fish. Use a de-chlorinator to cleanse your water to keep the levels at 0.

High ammonia, nitrate, and nitrite content also affect fish tank water quality. Nitrates promote algae growth, while nitrites lower oxygen levels in the fishes’ blood. Nitrite and nitrate levels must be between 0.0 to 0.5 mg/L and 0 to 40 mg/L, respectively, via consistent water changes. Ammonia, which enters the tank water through biological processes, such as fish waste, should never rise beyond 0.25 mg/L to avoid making your aquatic pets sick. 

Keep your aquarium water healthy with professional assistance from Gerber’s Tropical Fish, the freshwater fish center serving enthusiasts throughout Cincinnati and Dayton, OH, since 1988. Call (937) 297-0515 with fish tank questions or stop by the store for personalized help. Review the latest specials online and like the Facebook page for more tank tips.