Ammonia (NH3-4)
Natural Seawater Value: 0.010 mg/L
Acceptable Range: 0.000 to 0.050 mg/L
Any ammonia level above 0.05 mg/L is a cause for
concern, and the source should be found and corrected.
Nitrite (NO2)
Natural Seawater Value: 0.010 mg/L
Acceptable Range: 0.000 to 0.100 mg/L
Levels of 0.05 or less are
of little concern. If the levels are higher than this, the source should be found
and corrected.
Nitrate (NO3)
Natural Seawater Value: 0.050 mg/L
Acceptable Range: 0.000 to 25 mg/L
Nitrate is not toxic in and of itself, but a rising level is
indicative of deteriorating water conditions, and any level above 5.0 mg/L in
reef aquariums is a reason for concern.
Phosphate (PO4)
Natural Seawater Value: 0.030 mg/L
Acceptable Range: 0.000 to 0.250 mg/L
The use of a phosphate absorbing resin is recommended to keep phosphate
levels below 0.05 mg/L.
Silica (Sio2-3)
Natural Seawater Value: 0.040 mg/L
Acceptable Range: 0.000 to 0.500 mg/L
Any level above 0.3 mg/L may cause a diatom bloom in
the aquarium.
Potassium (K)
Natural Seawater Value: 390 mg/L
Acceptable Range: 350 to 450 mg/L
Potassium is an important constituent of seawater, being found in
almost the same concentration as calcium. Potassium is important for
neurological functions in fishes, as well as being a critical plant nutrient
required by zooxanthellae and macro algae.
Calcium (Ca)
Natural Seawater Value: 400 mg/L
Acceptable Range: 350 to 450 mg/L
Calcium is a critical parameter for coral growth in reef aquariums, and
chronically low levels will cause coral mortality and loss of coralline algae and
other invertebrate species.
Boron (B)
Natural Seawater Value: 4.6 mg/L
Acceptable Range: 3.0 – 6.0 mg/L
Boron is a
significant portion of your aquarium pH and water buffering capacity, and is
crucial to maintaining appropriate calcium levels, as well as being essential to
several biological processes, including macro algae growth.
Molybdenum (Mo)
Natural Seawater Value: 0.01 mg/L
Acceptable Range: 0.0 to 0.12 mg/L
Molybdenum is important to microbial activity in
the aquarium filter, and may also be important to stony coral health and
reproduction.
Strontium (Sr)
Natural Seawater Value: 8.1 mg/L
Acceptable Range: 5.0 to 12.0 mg/L
Strontium is
important to coral growth, as they incorporate strontium ions into their
skeletal mass, particularly SPS corals. It is also important to coralline algae
growth.
Magnesium (Mg)
Natural Seawater Value: 1280 mg/L
Acceptable Range: 1100 to 1400 mg/L
Magnesium is a very important part of the water buffering system, and is
incorporated into coral skeletons. It is also critical to any photosynthetic
processes.
Iodine (I¯)
Natural Seawater Value: 0.060 mg/L
Acceptable Range: 0.030 to 0.090 mg/L
Please be advised that many iodine supplements are difficult to dose
accurately, and “above normal” readings are easy to achieve with common
iodine additives.
Copper (Cu++)
Natural Seawater Value: 0.030 mg/L
Acceptable Range: 0.000 to 0.030 mg/L
Copper is fatal to marine invertebrates at levels as
low as 0.05 mg/L for many species.
Alkalinity (meq/L)
Natural Seawater Value: 2.5 meq/L
Acceptable Range: 2.5 to 5.0 meq/L
Maintaining an appropriate alkalinity is crucial to maintaining a
healthy aquarium. A fluctuating alkalinity will lead to serious problems in
maintaining an appropriate pH, as well as problems keeping calcium and
magnesium levels within required ranges.
