Calcium (Ca)

NSW level- 380-400ppm Aquarium level- 400-450ppm (aim for a stable and balanced level within this range). Too little

• Reduced coral calcification and possibly a reduction in overall coral colours depending on the coral.

Spot on

• Optimal coral calcification, better colours, healthy coraline algae growth.

Too much

• Abnormal coral growth, out of balance magnesium and alkalinity ratio that results in retarded coral growth and deformed coral shapes.

Magnesium (Mg)

NSW level- 1290ppm

Aquarium level- 1200-1380ppm (aim for a balanced & stable level)

Too little

• Polyp bailout in LPS, tissue loss in SPS, slowed or abnormal growth in SPS & browning of corals (SPS particularly).

Spot on

• Optimal calcification and skeletal strength. A good ratio of magnesium to calcium is 3.1-3.3x that of calcium.
• Eg, calcium at 420ppm and magnesium at 1300-1380ppm.
• Stability is always key.

Too much

• Calcium becomes more soluble which prevents corals from precipitating (building) a skeleton as effectively as normal.

Iron (Fe)

NSW level- 0.003-0.1ppm

Aquarium level- Iron depletes rather fast so a constant but small dosage is recommended.

Levels of up to 5 times that of Natural Sea Water can be maintained if your aquarium is using the element.

Too little

• Pale corals, reduced macro algae growth.

Spot on

• Iron helps Zooxanthellae populations so pale corals can be helped to darken up to a normal & healthy level.

Too much

• Overly green corals, unwanted algae & excessive Zooxanthellae production.

 

Iodine (I)

NSW level- 0.064ppm

Aquarium level- Commercially available test kits for iodine can be tricky due to the chemical having a few forms and bonds to other elements but they do well enough to keep your aquarium as close to natural seawater levels as possible.

Too little

• Faded blue/purple corals

Spot on

• Rich purple and blue corals (particularly Acropora). Iodine also helps the coral to perform various internal functions.
• It’s also very helpful for soft corals, anemones and invertebrates like shrimp.

Too much

• Levels at or above 0.1ppm can be quite detrimental to the aquarium.
• Bacterial populations are in great danger at higher levels and once they start dying the snowball effect of ammonia can mean a wipeout.

Bromine (Br)

NSW level- 67.3ppm

Aquarium level- 65-68ppm but levels must be kept at the higher end of this range for corals to be able to use the element, but low levels don’t appear to have a dramatic effect on corals.

Dosing is best done in very small but regular amounts and tested via ICP-OES occasionally to be sure of your dose rates.

Too little

• browned polyps in SPS and a dull appearance

Spot on

• Bromine helps regulate Zooxanthellae. It helps with blue Acropora colouration when iodine is within a healthy range of 0.04-0.06.
• Careful and monitored dosage will bring out a beautiful metallic sheen to corals but especially noticeable in SPS.

Too much

• Bleaching is the main concern with overdose.

Strontium (Sr)

NSW level- 8-9ppm
Aquarium level- 8-10ppm

Too little

• Brittle coral skeleton & slower calcification.
• Coral colours loose their lustre and potentially a loss in some green pigments.

Spot on

• Important to coral calcification, helps with green colouration of some corals.

Too much

• In the extreme event of a massive overdose it will be lethal to corals but levels can hit 30ppm with no massive issues, ideally you don’t want this though.
• Levels over 18ppm May cause undesirable algae.

Chromium (Cr)

NSW level- 0.0002ppm

Aquarium level

• Chromium is very light sensitive so it depletes fairly quickly in reef aquariums.
• Carefully adding a balanced supplement and utilising ICP-OES testing is the easiest way to monitor your chromium levels.

Too little

• Minor coral growth issues and potentially dull or flat looking corals.

Spot on

• Calcium uptake is optimised and fluorescent proteins are produced easier.

Too much

• Bleaching or paling of corals eventually leading to death.

Zinc (Zn)

NSW level- 0.005ppm

Aquarium level- Zinc is used to regulate Zooxanthellae in SPS coral, it thins the Zoox out and allows the coloured pigments to be seen underneath.

A quality supplement and occasional ICP-OES testing will ensure that you have this element covered.

Too little

• Potentially darker/brown corals but there are other ways to remedy this without solely relying on Zinc.

Spot on

• Controls the population of Zooxanthellae to allow brighter corals.

Too much

• Overdoses will stop the uptake of calcium and alkalinity supplements and bleached corals (expelled Zooxanthellae) are the result of an overdose.

Potassium (K)

NSW level- 380-450ppm.

Aquarium level

• Potassium is a very important element with many roles in the aquarium.
• It promotes Zooxanthellae growth, aids in chromoprotein production and it even makes up a small part of the skeletal structure.
• Daily dosing is best and aim for 380-400ppm.

Too little

• Tissue necrosis (STN-Slow Tissue Necrosis) typically starting from the base of the colony in SPS, poor or deformed growth & pale colours.

Spot on

• Rich Blue/violet colouration in Acropora. Red/pink colouration in Montipora and Seriatopora corals is vibrant and deep.

Healthy Zooxanthellae production within the coral. Too much

• Tip burn in Acropora, slowed growth & browning of corals.

Boron (B)

NSW level 4.3ppm

Aquarium level 6-8ppm

Too little

• Lacking red & pink pigments, potentially lower or unstable pH values.

Spot on

• Promotes normal coral skeleton calcification, enhances red pigments & aids in stabilising pH in the optimal range of 8-8.3.
• Boron also works to inhibit excessive zooxanthellae production therefore brighter looking corals.

Too much

• Bleaching or pale corals.

Manganese (Mn)

NSW level- 0.0004ppm Aquarium level

• An essential element at the right levels. You can dose slightly more if you use an algae reactor as it is consumed fast and back off the dose when you clean out the algae reactor.
• Iron & Manganese work together in many ways so using a good quality balanced supplement will ensure your aquarium is being delivered what it needs in the right ratio.

Too little

• Macro algae not growing or slowed growth, poor red colouration in corals.

Spot on

• Manganese helps with the reproduction of algae such as Zooxanthellae in LPS & SPS coral.
• Also with the right levels or slightly elevated levels it will help with rich red pigments underneath the Zooxanthellae.

Manganese also aids in keeping macro algae healthy. Too much

• Coral polyps can become retracted and undesirable algae may begin to grow.
• Manganese is UV Light sensitive so the risk of overdose is slightly lower due to how fast it’s depleted and utilised by the aquarium.

Cobalt (Co)

NSW level- 0.00039

Aquarium level

• Cobalt is another element that will be difficult to constantly test for but in a quality marine supplement it can be delivered at safe levels that allow it to be used by corals in ratio to other elements, however we recommend occasional ICP testing to ensure your dosage is on track with the amount of corals you have.

Cobalt is also sensitive to light and depletes this way too. Too little

• Corals can become sluggish in their ability to produce sugars.

Spot on

• Cobalt at the right level is important for vitamin & folic acid uptake.

Too much

• Heavy metal toxicity causing stress, bleaching and STN (Slow Tissue Necrosis)

Fluoride (F)

NSW level- 1.3ppm Aquarium level

• Fluoride is best measured with occasional ICP-OES testing to help maintain it as close to 1.3ppm as possible.
• Also using a quality, balanced supplement in your aquarium will help you deliver this element at safe levels along with its other halogen type elements that we covered in previous posts (Iodine & Bromine)

Too little

• Potentially dull blue or violet colours and some other internal shortfalls such as a brittle coral skeleton structure.

Spot on

• Properly regulated Zooxanthellae populations (by regulated we mean that Fluoride expels Zoox), optimal coral calcification similar to how strontium affects calcification & rich blue and violet colouration.

Too much

• Bleaching or stripped flesh on corals.

Nickel (Ni)

NSW level- 0.0066

Aquarium level

• Nickel is another micro element that you will need to do occasional ICP-OES testing for.
• As long as this element is present in the system at level not above that of NSW you will see the benefits of its addition.

Too little

• Corals can become sluggish in their ability to uptake and process amino acids.

Spot on

• Nickel plays a big role in amino uptake and allows the corals to take up calcium at optimal speeds.

Too much

• Heavy metal toxicity causing bleaching, RTN or tissue/polyp bailout.

Copper (Cu)

NSW level- 0.003ppm

Aquarium level

• Copper is another light sensitive element so take this into consideration when dosing.
• Test kits commonly available to aquarium hobbyists don’t test in ranges low enough for corals, they are usually for copper treatment on parasites.
• We recommend the occasional ICP test to ensure you have the dose set properly.

Too little

• No discernible effects on corals with low or severely lacking levels.
• Copper at higher levels is generally used in aquariums for treating parasites while in quarantine.

Spot on

• Copper works in a similar way to zinc in that it regulates Zooxanthellae to allow colour pigments to show through.

Too much

• Excessive paling/bleaching of corals and sluggish movements or death of invertebrates.

Information provided by:

Shane Coleman