Maintaining Proper Water Quality in the Home Aquarium
Drs. Foster & Smith Educational Staff

Maintaining proper water quality in the home aquarium.
Making sure your tank has all of the appropriate water parameters and environmental requirements the particular species needs is one way to reduce tank mortality.

Freshwater Parameters
The following chart is a general guideline of acceptable water parameter ranges for different types of freshwater aquariums, brackish water aquariums, and ponds. The water parameters listed are a general guideline for maintaining each specific type of aquarium or pond. Some species of fish, plants, or invertebrates may have more specific requirements, so please review each individual species description for more information.
German Blue Ram
Parameter Freshwater Community African Cichlid Freshwater Plants & Discus Brackish Pond
Temperature 72 - 82°F 72 - 82°F 76 - 86°F 72 - 82°F 33 - 86°F
pH 6.5 - 7.5 7.8 - 8.5 6.0 - 7.5 7.5 - 8.4 6.5 - 7.5
Ammonia 0.0 0.0 0.0 0.0 0.0
Nitrite 0.0 0.0 0.0 0.0 0.0
Nitrate < 50 ppm < 50 ppm < 30 ppm < 50 ppm < 50 ppm
Alkalinity (Carbonate Hardness) 4 - 8 KH 10 - 18 KH 3 - 8 KH 10 - 18 KH 4 - 8 KH
General Hardness 4 - 12 GH 12 - 20 GH 3 - 8 GH 12 - 20 GH 4 - 12 GH


Marine Parameters
The following chart is a general guideline of acceptable water parameter ranges for different types of tropical marine aquariums. Some types of displays such as FOWLR (Fish Only With Live Rock) aquariums have a broader range of parameters than a reef aquarium. This is due to the delicate nature of corals and invertebrates that are commonly maintained in a reef aquarium. Some species of fish, plants, or invertebrates may have special requirements, so please review each individual species description for more specific information. For reference we have also provided the average water conditions measured on tropical coral reefs across the world.
Yellowstripe Maroon Clownfish in Anemone
Parameter Suggested Level:
Reef Aquarium
Suggested Level:
FOWLR Aquarium
Average Level:
Coral Reefs
Specific Gravity 1.023 - 1.025 1.020 - 1.025 1.025
Temperature 72 - 78°F 72 - 78°F 82°F
pH 8.1 - 8.4 8.1 - 8.4 8.0 - 8.5
Alkalinity 8 - 12 dKH 8 - 12 dKH 6 - 8 dKH
Ammonia (NH3) Undetectable Undetectable Near Zero
Nitrite (NO2) Undetectable Undetectable Near Zero
Nitrate - Nitrogen (NO3) < 1.0 ppm < 30 ppm 0.25 ppm
Phosphate (PO4) < 0.2 ppm < 1.0 ppm 0.13 ppm
Calcium 350 - 450 ppm 350 - 450 ppm 380 - 420 ppm
Magnesium 1250 - 1350 ppm 1150 - 1350 ppm 1300 ppm
Iodine 0.06 - 0.10 ppm 0.04 - 0.10 ppm 0.06 ppm
Strontium 8 - 14 ppm 4 - 10 ppm 8 - 10 ppm