Magnesium dosing

[wasp]

Hi Randy, I'm using your two part recipe.
For some reason my tank uses quite a lot of magnesium, to maintain it I have to dose around twice the epsom salt mix than what is recommended in your recipe.
With the extra sulphate ions, just wondered if this will be safe long term? I'm doing around 20% water change per month.

[Randy Holmes-Farley]

It is certainly possible that some aquaria may have a higher demand for magnesium than others, as different organisms use different ratios of magnesium to calcium. Coralline algae especially use a lot.

If I needed to add more magnesium than the recipe called for, I'd probably use either magnesium chloride (which you would have to try to locate; it is soemtimes used in the US to melt ice), or use a commercial magnesum supplement.

I would worry about too much sulfate from a lot of Epsom salt use. I do not know that elevated sulfate is a problem, or what exactly would be a symptom, but I'd try to avoid it.

[wasp]

OK Thanks, yes finding magnesium chloride is the problem, unless I pay the somewhat inflated LFS prices.

[Keigo]

me too.. my mg dosing is high.. and I'm worry too.. about this espom dosing.. look like I have no choice to go for Mg chloride.. but it's very hard to find one unless pay high price for these LFS Mg..

[Randy Holmes-Farley]

Greg Hiller recently organized a group buy (for the Boston Reefers) of very inexpensive magnesium chloride:

http://216.235.242.50/forums/showthread.php?t=3568

[wasp]

Well I'm in New Zealand, but I've just done a net search and been able to find some REAL cheap, around $10.00 fo a 60 lb bag.
Once I get this, should I add in any magnesium sulphate at all, or just pure magnesium chloride?

[Keigo]

wasp.. can share where u find it.. cause I'm in asia.. would love to get them too..
thanx

[Randy Holmes-Farley]

This article gives a good DIY based on having both Epsom salts and magnesium chloride:

A Homemade Magnesium Supplement
http://web.archive.org/web/20030624220704/http://www.animalnetwork.com/fish2/aqfm/1999/june/bio/default.asp

(the link is down now, but should be up later)

[wasp]

Keigo, these guys- http://ravensdown.co.nz/products/national2004/animal_health.htm Turns out they sell it in a store just up the road from me, NZ$ 13.00 (around US$ 9.00) per 25 kilogram bag.
Not sure how you would get it to you though, however could email them and ask.
Randy thanks, Good Article!

[bertoni]

Aquatic Tech sells this reagent grade package:

http://aquatictech.com/chemicals.html

I don't know whether it's appropriate or even a good price, but it's cheaper than what I pay now, I think.