What Are the Essential Water Parameters I Need to Monitor?

Maintaining stable water parameters is one of the most important aspects of fish keeping. Unlike in the wild, where water volume buffers changes, aquariums are closed systems—meaning small imbalances can quickly become serious problems. Regular testing is the key to keeping your aquatic pets healthy and thriving.

1. Ammonia (NH₃/NH₄⁺)

A highly toxic compound from waste and decay. Should always be 0 ppm. Any presence indicates a filtration issue.

2. Nitrite (NO₂^-)

Another toxic nitrogen cycle byproduct. Should also remain at 0 ppm in a mature, healthy tank.

3. Nitrate (NO₃^-)

Less toxic but still harmful in excess. Keep < 40 ppm—preferably below 20 ppm for sensitive species. Controlled through water changes.

4. pH

Affects fish metabolism and stress. Aim for consistency in the range your species prefers (often 6.8–7.8 for community tanks). Avoid sudden shifts.

5. General Hardness (GH)

Measures calcium/magnesium concentration. Influences osmoregulation. Requirements vary—research species preferences. You can use Seachem Equilibrium to manage GH.

6. Carbonate Hardness (KH)

Also known as alkalinity. Helps stabilize pH. Higher KH = greater buffering capacity and better pH stability. You can use Seachem Alkaline Buffer to manage KH.

7. Temperature

Most tropical species thrive between 75–80°F (24–27°C). Sudden changes can weaken immune systems—use a reliable heater and thermometer.