Author Topic: Balancing Alk and Calcium  (Read 2478 times)

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Offline mikeydog

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Balancing Alk and Calcium
« on: November 13, 2003, 04:58:28 PM »
After last nights discussion about the levels in my tank, and since I just added a Calcium Reactor, and have no clue about Alk and Calc, I decided to do some studying.  I found a very good article that really helped me understand the differnce and similarities of Calcium and Alkalinity in you Reef Tanks.
125 gal (setup 11/02)
150lbs sand, 110lbs liverock
1.255sg 80F
40gal DIY Sump, ASM G-4 Skimmer
Duel Chamber MSS Calcium Reactor
2x250w DE 10k MH
1x250w DE 14k MH
3x165w VHO lighting


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Balancing Alk and Calcium
« Reply #1 on: November 13, 2003, 06:02:18 PM »
Cool, some of the most important elements in the tank. Don't try to bash your head in to get them perfectly balanced either. Becuase most often, you ain't going to get it perfectly.

Offline Ed

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Balancing Alk and Calcium
« Reply #2 on: November 14, 2003, 06:26:24 AM »
I have heard that magnesium levels affect calcium levels readings?   I think that may have been the problem with guy in this article?  :?:  I am only guessing.
come over and see..:)


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Balancing Alk and Calcium
« Reply #3 on: November 14, 2003, 08:35:52 AM »

Magnesium in Marine Aquaria

Magnesium has tremendous biological and chemical relevance to reef aquaria. Fortunately for reefkeepers, it is present in abundance in seawater. There is, in fact, a fairly high turnover of magnesium in reef aquaria with rapidly calcifying organisms. The primary reason that magnesium is not more of a daily concern to aquarists is that the reservoir of magnesium in seawater is very large. Magnesium might be compared to a large lake, with the lake level only slowly responding to changes in inputs from rivers and export via evaporation and the outlet. Consequently, maintenance of magnesium levels is not typically a rapidly developing problem. If using an appropriate salt mix, it may never become a problem for many aquarists.

Meaning that magnesium is normally not a thing for any of use to be concerned with.

The other major source is calcium supplements. Many of these supplements contain magnesium, either by “accident” (as in the case of calcium carbonate with impurities of magnesium carbonate that is used in CaCO3/CO2 reactors) or because magnesium is intentionally added by manufacturers.

Then if you perform recommended water changes, these levels will balance out, unless you use a bad salt mix.

Another potential source of magnesium is fish food. Magnesium is present in many such foods at fairly high concentrations, but not enough to have a significant impact on typical levels of magnesium (~1285 ppm).

This means that even when you feed your aquarium large amounts of food that contains large amounts of magnesium, this will not impact the levels in your system. Probable only adding organic and inorganic phosphates and increasing nitrates would be you concern here.

A 100-gallon aquarium contains about a pound of magnesium! In order to raise that same aquarium by 200 ppm of magnesium, one would need to add on the order of 2 pounds of dry magnesium salts!

Which shows that the increasing or decreasing of  magnesium is a very slow process and it would take a sever change to the chemistry to the system to get it to change.

Randy then concludes with the idea that aquarium keepers are probable more concerned with increased magnesium levels then depleted levels.

Magnesium is an important ion for reef aquarists. In addition to its many biological functions, it serves to prevent the excessive precipitation of calcium carbonate from both seawater and aquarium water. Since both calcium and alkalinity are very important to organisms that we keep, making sure that they are not lost to excessive precipitation is an important part of aquarium husbandry.

It is my belief that any on that has problems with magnesium in their systems is directly related to their lack of good reef tank husbandry. (Water Changes)

Remember the old saying, "The solution to pollution is dilution"? The same is true when one does good water changes using RO/DI and good saltwater mixes. Then one would never have to worry with playing scientist with chemicals other then calcium/alk.