calcium level low

[cannondale]

anyone know why my calcium level always around 300-340. i adding it every day in a 4 x 2 x 2 tank. but it seems like cant acheive 400 marks.

or may be my calcium not good enough? change to other brand?

[Ekia]

Check your Magnesium

[Reefbum]

anyone know why my calcium level always around 300-340. i adding it every day in a 4 x 2 x 2 tank. but it seems like cant acheive 400 marks.

or may be my calcium not good enough? change to other brand?

Yup check your magnesium and akalinity.Low levels of clacium doesn't mean time to add in more calcium.In fact it may worsen.

[slcw]

anyone know why my calcium level always around 300-340. i adding it every day in a 4 x 2 x 2 tank. but it seems like cant acheive 400 marks.

or may be my calcium not good enough? change to other brand?

May be this note taking (article) may help u understand:

As student in secondary school I always fail either my physics or chemistry. Each bears 50% of the combined subject. When I failed physics, the physics teacher reminds me I should pay more attention to the subject, and when I do, I failed my chemistry and passed my physics. There never seem to be a balance between the two. Similarly in our aquariums, there is also imbalance, when there are more acids (hydrogen ions) than hydroxyl ions, there is decline in pH.

As I am puzzled about the choice of maintaining calcium levels and alkalinity, I found myself studying a failed subject of my past. As mentioned in another thread, you cannot have both high calcium levels and alkalinity. They are mutually exclusive.

As I dived into the topics of pH, alkalinity and calcium to better understand how each dose I pour / add into the aquarium or my lack of regular maintenance will contribute the health and growth of my corals. This is my notes taking:

pH is the degree to which a solution is acid or alkaline. Pure water has a pH of 7, which is neutral. A solution less than 7 has more hydrogen ions than pure water is said to be acidic. While a solution with fewer hydrogen ions than pure water has a pH greater than 7 and is said to be alkaline.

These ions are charged molecules. Hydrogen ions carry a positive charge, as signified by the chemical shorthand for this ion, H+. In a sample of pure water, ions would exist in pairs, with each positively charged ion matched by a corresponding negatively charged ion, so the overall charged would be balanced by hydroxyl ions (OH-).

Adding hydrogen ions to the water would cause the pH to decrease, add hydroxyl ions would cause the pH to increase. Several books described the natural seawater to be at the range of pH of 8.0 to 8.4.

Alkalinity is the degree to which a solution maintains its pH when acid is added is the alkalinity of the solution. Carbonate hardness or KH both used interchangeability in this hobby. In reality total alkalinity in sea water is slightly higher than carbonate hardness. This is because carbonate hardness is a measure of only the contribution of carbonate (CO3-2) and bicarbonate (HCO3-) to total alkalinity. In the sea, various other negatively charged ions, such as borate (BO3-3) and hydroxides (OH-) contribute to the total.

To better understand the concept of alkalinity, we discuss the neutralization reactions, The general formuale for neutralization reaction is written as follows:

H+ + OH-  H20

Second, note both Hydrogen and hydroxide ions are involved. Third, consider the different chemical compounds will yield up different amounts of hydrogen or hydroxide ions when dissolved in water.

An example is Nitric acid, HNO3, yields only 1 hydrogen ion per molecule while sulfuric acid, H2SO4, yields two.

Similarly, calcium hydroxide, Ca(OH)2, yields 2 hydroxyl ions per molecule, and sodium hydroxide, NaOH, yields only 1.

In layman terms, the more hydrogen ion you have in a solution the more likely will the pH will move towards acidic. To further add, a compound say NaCl is added to the water, it breaks up into ions (Na+ and Cl-). These broken up ions will combine with other ions in the aquarium. For every positive ion will be matched with a negative ion.

In an aquarium, measuring alkalinity, we need to determine how many equivalents of acid there are in order to combine completely with bicarbonate, carbonate, borate, hydroxide and other ions without adding an excess of hydrogen ions. Chemist performs a titration test, adding acid solution drop by drop to determine the endpoint where the pH will drop drastically. The result is pH remains stable for the first few drops of acid and drops precipitously as the end point is reached. This shows the initial stability of seawater’s pH is a buffer. Buffers are solutions that resist pH changes. That is why alkalinity or KH is referred as the buffering capacity.

The alkalinity of seawater is around 2.0 to 2.5 meq/L. to convert to carbonate hardness (dKH) multiply this by 2.8 to yield about 6-7 dKH. In aquarium, it is recommended to maintain higher dkH as higher alkalinity offsets the accumulation of acids of a closed system aquarium. These acids come from several sources. The primary ones are carbon dioxide from respiration, nitric acid from biological filtration and organic acids from metabolic wastes.

This study made me aware the reasons why acids produced by fish and when the lights are off contribute to the decline in pH and the reasons behind why we add Kalkwasser during lights out

[slcw]

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Calcium

when alkalinity is high, skeleton building can still occur, even when calcium is low. But when both are low, corals cannot thrive.

Converserly, raising calcium above 550 mg/L will result in precipitation of calcium carbonate as chalk and a drop in alkalinity and calcification is made more difficult.

according to the experts, they say allowing the pH to go higher than 8.6 will impede calcium maintenance as calcium carbonate will spontaneously precipiate as the pH rises, once again robbing the system of both Ca and carbonat ions. (I personally dun quite figure out this)

Maintaining the proper balance is best accomplished thru use of automated sys for dosing lime water and electronic pH meter. manual add by hand and test kits u have to give more room for error.

there are more towards calcium and other factors affecting calcium n alkalinity...I think will pen off here...anyone interest can catch anybook on this. credits goes to John Tullock for his imparted knowledge.

on my side, having read, i think unless u have good calcium reactor media and proper fine tuning the co2 the investment will pay as excessive co2 will decrease pH is left unnoticed. Plus the use of pH controller is better. As for as Kalkwasser, i think we have a few brands around, which i think deep_end can access it. The reactor for kalkwasser is cheaper but, the investment can come close to Ca reactor. I think kalkwasser is time tested and excellent to supplement the water top ups.

few books have articles in Ca reactor compared to vast kalkwasser. US and its authors have yet to comment in detail. in Euro Ca reactor are more widely used.

[Reefbum]

Something I would like to share regarding pH which I read somewhere.Improper dosing of calcium can mask the true value of pH.That's why it is paramount to check magnesium if you are dosing calcium so that your pH don't fluctuate too much.

Food for thought:Why is it that the pH range is so small compared to other parameters?

[nim75sg]

Monitor the magnesium level as it will drops when you're dosing kalk.

[cannondale]

i dont have the magnesium tester