magnesium

[grouper therapy]

Has anybody here used dolomite in their calcium reactor for the supplementation of magnesium?? Please give provide info if so.

 

[dakota9]

Off topic just a little, but didn't people used to use that as substrate back in the old days?

 

[dannybradley]

I've read it takes a much lower pH to melt than araganite. I believe you have to get below 6 to use it effectively.

 

[enderg60]

yup you will need a very low ph(like around 6.0) and you will need much larger calcium media(like 1/2" and larger) to keep it from turning to mush.

Or knowing you, just a second reactor....

 

[mojo]

I asked SeaChem about this when they gave a talk last year (or was it the prior year), and the guy said that it wasn't typically necessary to add anything to a calcium reactor for additional magnesium. When the aragonite (or similar substance) in the reactor breaks down, it releases magnesium that was bound within, in the same proportion that it bound in there.

I've tested mine on a regular basis, and can't tell for sure if this is actually the case, since I've been purposely running a high Mg level (1700+).

 

[sailfish]

I have some in my reactor for about 3 months and as far as I can tell it has not helped much. I still have to dose my water changes to keep my mag 1300 plus.

Now I used zo mag and I sifted all the small particulate out of it because I used it mixed in with larger size media.

I noticed that some European reactor units have a specially designed unit just for it.

I have thought of making my on. All you really need is a T of your regulater,
bubble counter, and another PH controller or a duel unit.

Joe

 

[enderg60]

The only problem I see with adding it to your calc reactor is the dosing rate. The ammount you put in there effectivly changes your dose rate, and since everyones tank is different I personally would rather just have a second reactor.

As joe said, all you need is a T,a bubble counter, a regulator and a second PH monitor.

At least thats how I plan to do it, when my system outgrows the 3part system.

 

[acroholic]

mojo;311708 wrote: I've tested mine on a regular basis, and can't tell for sure if this is actually the case, since I've been purposely running a high Mg level (1700+).

Chris,
Is that Mag level doing what you want it to?
Dave

 

[mojo]

It's hard to say without a control group. The bryopsis seems to have slowed or recessed some, but maybe it's due to being balanced with nutrient uptake. Or maybe it's cutting down on feeding.

I'm going to continue maintaining high magnesium for a while and see what happens- it doesn't seem to be having any other effects, other than on my wallet...

 

[tdwyatt]

Dolomitic calcium (dolomitic limestone) is 44 to 45% magnesium, so not only will you be overdosing the tank with Mg (which is a problem for bivalves, it acts as a muscle relaxant and shucking aid for clams and oysters), but you'll also be delivering that much less calcium (if the medium is 45% Mg, that means there is only 55% Ca++). PLUS YOU'LL BE WASTING A TON OF CO2 to get it to dissolve in seawater. It also changes the total pKa of the buffer package in seawater as the amount of Mg goes up, and may cause chronic issues with daily ave pH (probably why it seems to work in the treatment of tanks with Bryopsis spp.</em> blooms, but that is speculation on my part).

In addition, low Mg++ is usually a symptom of long term use of two part hermatypic additives that result in sodium and chloride accumulation in the water. There are very few organisms that actually consume Mg++ in amounts to affect water column concentration in excess of what water changes fix. There are a few spp. of Corallinaceae</em> incorporate it in their crustose deposits at the same concentration it is found in the water column, but they are rare in aquaria. If you are having problems with chronically low Mg++ and you perform regular water changes, either you supplement a lot with 2 part additives (or one of the two) or you're slowly losing water from the tank somewhere (which gradually drops salinity and your total Mg++ over time).


HTH