Domolite lime and other lost arts...

StirCrazy · #20 01-23-2002, 10:44 PM

<blockquote>quote:<hr>Originally posted by powerreef:
I have been keeping a SW aquariums for 19 years and am one of those that used to used Dolomite as a substraight.<hr></blockquote>

How long was your tank running on Dolomite?

<blockquote>quote:<hr>Originally posted by powerreef:
Thier have been many studies measuring the effect Magnesuim on aquaria, and it has been found that animals exposed to high mag concentrations in SW begin to show significant relaxation (ie: works as anaethesia) and prolonged expose causes mortallity in almost all species..<hr></blockquote>

Can you post some of the links to thease studies please, I haven't been able to find anything on this yet and I would liek to read it.

<blockquote>quote:<hr>Originally posted by powerreef:
Another thing that scares me is the effect that Magnesium has on alk and cal. As i'm sure you know magnesium will slow the percipitation of cal.by attaching its ion to the carbonate ion of calcium carbonate. What effect would this have on calcium if it sat in a tank with such high levels of mag<hr></blockquote>

you would be able to obtain higher calcium levels.

<blockquote>quote:<hr>Originally posted by powerreef:
Another thing to remember is in seawater, more than half of the carbonate ions present at any given point in time are ion-paired to magnesium, and this substantially reduces the free concentration of carbonate ions available to precipitate with calcium.<hr></blockquote>

this is TRUE, and it is a good thing. if the Mg didn't pair with the carbonate ions the calcium would.. and if calcium did pair it would drop out of solution and create more sand. exactly what you don't want . now because the magnesium is causing more calcium to stay in solution that means there is more calcium available for your coarls and other creatures (that require calcium) this is one of the benifits of adding magnesium to your system, it allows you to have HIGHER Ca levels. I would hazard to guess that anyone with over 450ppm ca has a higher magnesium level than natural sea water.

<blockquote>quote:<hr>Originally posted by powerreef:
I geuss what i'm trying to say is that magnesuim at natural levels is good , but at high levels the fact that joins with other minerals and chemicals and produces biproducts is not good.<hr></blockquote>

ok you confused me on this one and I wasn't sure what to say but Magnesium is fairly non reactive and dosent combine with other metals. to back this up I will use a quote from a chemmist who is a reefer.

"Interestingly, the average residence time for a magnesium ion in seawater is tens of millions of years, substantially longer than calcium (a few million years) and aluminum (100 years), but less than sodium (about 250 million years). In a sense, this is an indication of how reactive magnesium is: it stays in seawater a long time because it's fairly unreactive, but it does get taken out of solution more readily than does sodium." by Randy Holmes-Farley

now what I think you might have been talking about is what he referd to as "Poisoning of Growing CaCO3 Surfaces". in fact the magnesium doesen't combine with the calcium but the magnesium carbonate forms a coating around the calcium carbonate and when it is large enuf it precipatates out of solution. remember if something falls out of solution it is no longer a concern as it can't interact. this is one of the ways the level of magnesium in a solution is controled.

I have to say this post made me do a lot more searching and I had to reread a lot of stuff to be sure on what my instints were. now having said all that I am interested in reading thease studies on the higher magnesium levels you were talking about.

Steve