Below are recommended water parameters that can be used as a guideline for general marine tanks.
pH - 8.2 to 8.4
Salinity - 30.5 to 35 (or 1.023 to 1.026 Specific Gravity (SG))
Calcium - 380-420
Alkalinity - 6 to 9 dKh (ideally 6.5 to 8.5 dKH) NSW levels
Magnesium - 1300 to 1350
Iodine - 0.04 to 0.06
Strontium - 8ppm or 8mg/l (NSW levels)
Potassium (K+) - 380-420
Nitrite - 0
Nitrate - less than 5
Phosphate - less than 0.01
Ammonia - 0
Calcium (Ca)
All calcareous animals, especially corals need calcium and carbonates to grow and flourish. However the growth rate of corals depends mostly on the zooxanthellae (algae) that live symbiotically within them. These algae present the coral with precious carbohydrates of their own metabolism. As they photosynthesize, they use carbon dioxide from the water, which enables the coral to precipitate calcium carbonate in its skeleton.
Natural sea water contains on average 400-410 ppm of calcium and is typically saturated at this level. It is important not to exceed 450 ppm, as super saturation can result in the calcium surplus precipitating out of the solution, taking desirable trace elements with it (commonly known as a snowstorm in a tank).
Alkalinity (KH or dKH)
Natural alkalinity and calcium concentrations are of special importance to ensure optimum growth and well-being of many invertebrates and calcareous algae in an aquarium. In many reef aquaria an increase of alkalinity and a decrease of calcium often occur.
Magnesium (Mg)
A sufficient supply of magnesium is as essential for the growth and well being of reef building coralline algae as calcium. It is one of the major constituents of seawater and is directly involved in algae photosynthesis, i.e. the conversion of carbon dioxide (CO2) and light into organic compounds. Magnesium helps in the calcification process of invertebrates and is essential to balance KH and Ca.
Iodine
Of all the trace elements found in natural sea water, iodine is associated with the widest range of effects. Iodine prevents goitre as an important component of the thyroid hormone. It also is essential for the hardening of the chitinous shell of crustaceans. Corallinaceous red algae deposit iodine in surface structures and gorgonias deposit it in the axial skeleton.
Experiments clearly show that idoine improves the adaptation to light and the colouring of anthozoa, especially of hard corals.
Due to its unstable nature in solution, iodine should be added to a marine aquarium on a regular basis in its most effective form, as elementary I2. Iodine demand increases with aquarium population density.
Strontium
A sufficient supply of strontium and carbon dioxide is as essential for the growth and well-being of reef-building corals as calcium. Both elements are supplied to the corals with the help of the zooxanthellae (algae) that live symbiotically within them.
Ammonia (NH3)
Ammonia Nitrogen, the first toxic stage of the nitrogen cycle.
Nitrite (NO2)
An Unstable form of nitrogen and the second stage of the nitrogen cycle.
Nitrate (NO3)
The final part of the nitrogen cycle which denitrifies in anoxic conditions and turns into nitrogen gas.
Phosphate (PO4)
An unwanted nutrient found in tap water, fish foods etc that feeds slime and hair algaes.
pH - 8.2 to 8.4
Salinity - 30.5 to 35 (or 1.023 to 1.026 Specific Gravity (SG))
Calcium - 380-420
Alkalinity - 6 to 9 dKh (ideally 6.5 to 8.5 dKH) NSW levels
Magnesium - 1300 to 1350
Iodine - 0.04 to 0.06
Strontium - 8ppm or 8mg/l (NSW levels)
Potassium (K+) - 380-420
Nitrite - 0
Nitrate - less than 5
Phosphate - less than 0.01
Ammonia - 0
Calcium (Ca)
All calcareous animals, especially corals need calcium and carbonates to grow and flourish. However the growth rate of corals depends mostly on the zooxanthellae (algae) that live symbiotically within them. These algae present the coral with precious carbohydrates of their own metabolism. As they photosynthesize, they use carbon dioxide from the water, which enables the coral to precipitate calcium carbonate in its skeleton.
Natural sea water contains on average 400-410 ppm of calcium and is typically saturated at this level. It is important not to exceed 450 ppm, as super saturation can result in the calcium surplus precipitating out of the solution, taking desirable trace elements with it (commonly known as a snowstorm in a tank).
Alkalinity (KH or dKH)
Natural alkalinity and calcium concentrations are of special importance to ensure optimum growth and well-being of many invertebrates and calcareous algae in an aquarium. In many reef aquaria an increase of alkalinity and a decrease of calcium often occur.
Magnesium (Mg)
A sufficient supply of magnesium is as essential for the growth and well being of reef building coralline algae as calcium. It is one of the major constituents of seawater and is directly involved in algae photosynthesis, i.e. the conversion of carbon dioxide (CO2) and light into organic compounds. Magnesium helps in the calcification process of invertebrates and is essential to balance KH and Ca.
Iodine
Of all the trace elements found in natural sea water, iodine is associated with the widest range of effects. Iodine prevents goitre as an important component of the thyroid hormone. It also is essential for the hardening of the chitinous shell of crustaceans. Corallinaceous red algae deposit iodine in surface structures and gorgonias deposit it in the axial skeleton.
Experiments clearly show that idoine improves the adaptation to light and the colouring of anthozoa, especially of hard corals.
Due to its unstable nature in solution, iodine should be added to a marine aquarium on a regular basis in its most effective form, as elementary I2. Iodine demand increases with aquarium population density.
Strontium
A sufficient supply of strontium and carbon dioxide is as essential for the growth and well-being of reef-building corals as calcium. Both elements are supplied to the corals with the help of the zooxanthellae (algae) that live symbiotically within them.
Ammonia (NH3)
Ammonia Nitrogen, the first toxic stage of the nitrogen cycle.
Nitrite (NO2)
An Unstable form of nitrogen and the second stage of the nitrogen cycle.
Nitrate (NO3)
The final part of the nitrogen cycle which denitrifies in anoxic conditions and turns into nitrogen gas.
Phosphate (PO4)
An unwanted nutrient found in tap water, fish foods etc that feeds slime and hair algaes.
Last edited:
