Advanced Reef Aquarium - Video Series: Alk/CA, Mg, Trace, GFO, CA reator

jrpark22000

Premium member
A good multi-part series on many factors of water chemistry presented in an easy to follow video series.



[video=youtube;GR8cWdW_IXI]https://www.youtube.com/watch?v=GR8cWdW_IXI[/video]

Calcium and Alkalinity are vitally important chemical parameters in reef aquariums. They are especially important in reefs with abundant populations of stony reef-building corals.

Calcium is one of the major ions in saltwater. It is the 5th most common ion in saltwater behind, chloride, sodium, sulfate, and magnesium. In most healthy reefs, the calcium level hovers around 425 ppm. Alkalinity is a little more difficult to explain than calcium. It is not a particular ion, but rather the buffering capacity of saltwater.




[video=youtube;zlB93PAD-jQ]https://www.youtube.com/watch?v=zlB93PAD-jQ[/video]

So what are trace elements exactly and what role do they play in our reefs? Saltwater with a specific gravity of 1.025 is made up 96.5% of water and “sea salts” that make up the remaining 3.5%. That 3.5% salt is made up of major elements and trace elements. The major elements are sodium, chloride, sulfate, magnesium, potassium, and calcium. What is left is a whopping 0.7% of that 3.5% fraction are the trace elements. There are around 70 different trace elements and they all fit into that 0.7%. The 14 most abundant are:
Chromium
Cobalt
Copper
Fluorine
Iodine
Iron
Manganese
Molybdenum
Nickel
Phosphorous
Selenium
Tin
Vanadium
Zinc
 

jrpark22000

Premium member
[video=youtube;ljAiZFPPJhE]https://www.youtube.com/watch?v=ljAiZFPPJhE[/video]

What is the role of Magnesium in the reef aquarium? The interactions of Magnesium, Calcium, and Alkalinity are closely tied to one another. Magnesium provides buffering capacity by bonding with carbonate ions. Carbonate being another word for alkalinity. Because Magnesium is binding up carbonate, it allows for more carbonate in the water than if Magnesium wasn’t there. When magnesium levels are appropriately high, it allows for the addition of calcium without the associated drop in alkalinity.





[video=youtube;4DeGg2_pK8o]https://www.youtube.com/watch?v=4DeGg2_pK8o[/video]

Granular Ferric Oxide (GFO) is a chemical filter media that inhibits algae growth in reef aquariums by removing phosphate from the water column. There are two types of GFO that Advanced Reef Aquarium carries, a standard absorption variety and a special high capacity variety that roughly has twice the absorption power.
 

jrpark22000

Premium member
[video=youtube;z948Zwr-hQA]https://www.youtube.com/watch?v=z948Zwr-hQA[/video]

A calcium reactor in short is a device that maintains calcium and alkalinity by dissolving calcium carbonate media and slowly dosing it back into the reef tank.

Calcium carbonate media just doesn't break down on its own. In order to dissolve it into calcium ions and bicarbonate ions, the water has to become more acidic. To achieve a slightly acidic environment we bubble carbon dioxide into the reaction chamber containing the media. When carbon dioxide mixes into water, carbonic acid is formed and thus you get a lower pH over time.
 
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