dolomite

I use 1/3 dolomite (calcium magnesium carbonate) and 2/3 aragonite. I get it from a farm supply store as chicken/turkey grit.

I haven't tried it yet, but there's a mineral called celestite (strontium sulphate) that you could also use in the reactor to buffer strontium. The residual sulphur would be utilized as a food source by pseudomonas for more efficient denitrification. You could supplement strontium and reduce nitrate at the same time, thus killing two birds with one very nice looking stone.
http://www.galleries.com/minerals/sulfates/celestit/celestit.htm
Here's a link to a dissolution study.
http://adsabs.harvard.edu/abs/1987GeCoA..51...63R
 
Good deal, I will need to read up on this topic. Sounds like an excellent way to keep things up, however, how do you deal with one being dosed too much and the other not enough? Obviously you change the ratio until you have the right amounts, but do you know initial measurements?
 
<a href=showthread.php?s=&postid=8759371#post8759371 target=_blank>Originally posted</a> by mwsmith15
Good deal, I will need to read up on this topic. Sounds like an excellent way to keep things up, however, how do you deal with one being dosed too much and the other not enough? Obviously you change the ratio until you have the right amounts, but do you know initial measurements?

Yes, it's the same process Chuck Norris uses to assure he doesn't kick your head clear off of your shoulders. Start slowly, and work your way up.
 
I would not add strontium sulfate. It will simply all dissolve at once. The sulfate added will not do anything useful, as there is already 2700 ppm of sulfate in seawater. FWIW, I do not recommend bothering to measure or dose strontium as I do not believe it has been demonstrated to do anything useful:

Strontium and the Reef Aquarium
http://www.advancedaquarist.com/issues/nov2003/chem.htm

Beware that dolomite should not be used to raise magnesium, but it can be used to maintain magnesium.
 
<a href=showthread.php?s=&postid=8765975#post8765975 target=_blank>Originally posted</a> by Randy Holmes-Farley
I would not add strontium sulfate. It will simply all dissolve at once. The sulfate added will not do anything useful, as there is already 2700 ppm of sulfate in seawater. FWIW, I do not recommend bothering to measure or dose strontium as I do not believe it has been demonstrated to do anything useful:

Strontium and the Reef Aquarium
http://www.advancedaquarist.com/issues/nov2003/chem.htm

Beware that dolomite should not be used to raise magnesium, but it can be used to maintain magnesium.


I was basing the need to supplement strontium on the study that Dr. Ron Shimek did. Strontium and sulphur were two of the five elements that were below natural sea water levels in the reef tanks he sampled. http://reefkeeping.com/issues/2002-12/rs/feature/index.php

Do you agree that trace elements should be at least the same value as natural sea water? I'm sure we both agree that there's no benefit to elevated values.

What is your position on the practice of dosing DSB's with sulphur? Wouldn't an increased demand for it arise from a larger colony of pseudomonas? Isn't dissolution the reason why natural sea water has a sulphate level of 2700 PPM? How does the "natural" production of sulphur in DSB's affect these levels?

I've heard many people make the claim that calcium reactors can't raise levels, only maintain them. I've not found this to be the case. I've found that calcium levels can be increased when gas injection and throughput are increased. Could this be true of your magnesium dissolution statement as well?

I'm not challenging your response. I'm just trying to learn more about a subject I know little about.
 
If sulfate is low in aquaria, it is because the starting salt mixes are low. But that aside, if you raise strontium from 0 to 100% of normal vlaues with strontium sulfate, you'll only raise sulfate by about 8 ppm, from 2700 ppm to 2708 ppm, which is a trivial boos t of only 0.3%.

if you want to boost sulfate, just use Epsom salt (magnesium sulfate heptahydrate) from a drug store to boost magnesium. I show the effect of that here:

Do-It-Yourself Magnesium Supplements for the Reef Aquarium
http://reefkeeping.com/issues/2006-07/rhf/index.php


Do you agree that trace elements should be at least the same value as natural sea water? I'm sure we both agree that there's no benefit to elevated values.

It is fine to have them as natural values, but in the case of strontium, supplementing it or not seems to make little difference to any organisms that we keep.

I've heard many people make the claim that calcium reactors can't raise levels, only maintain them. I've not found this to be the case.

Dolomite cannot be used to raise magnesium for the reasons given in this article:

Magnesium in Reef Aquaria
http://www.advancedaquarist.com/issues/oct2003/chem.htm


from it:

"It has been suggested that adding dolomite to CaCO3/CO2 reactors can help with magnesium problems. Dolomite is a material that contains both magnesium and calcium carbonate. If dolomite is being added to the reactor to maintain existing appropriate magnesium levels against the continual depletion via calcification (for example, if the calcium carbonate being used is too low in magnesium to maintain adequate magnesium) then this is a fine approach.

However, this method is unsuitable if the goal is to raise magnesium levels. The problem is that for every magnesium ion released from the dolomite, 2 units of alkalinity are also released:

MgCO3 ---> Mg++ + CO3--

Consequently, if one wants to raise magnesium by 100 ppm, the alkalinity will necessarily rise by 8.2 meq/L (23 dKH). The only way around this problem is to add a mineral acid (not vinegar) to the aquarium to reduce the alkalinity, and that may be more problematic than just adding magnesium in the first place."


I've found that calcium levels can be increased when gas injection and throughput are increased. Could this be true of your magnesium dissolution statement as well?

The same issue applies to calcium supplementation as well, although the ratio is not quite as bad. 1 meq/L (2.8 dKH) for each 20 ppm rise in calcium. So a 100 ppm boost pushes up alkalinity by 5 meq/L (14 dKH). There is no adjustment that can get around that problem.
 
Back
Top