Magnesium Level

[EMS503]

just picked up a Magnesium test kit (Sali Fert) at the advice of Barry (Clams Direct) to check my levels in my two tanks.
Both came back low 30 gal. reef is reading 1110ppm
and my 75 gal.reef is reading 1140ppm.
I read an article on the web which really did'nt help much or I just did'nt understand what was being said. But it stated some reasons for low Mag. levels are Salinity levels and type of salt being used. The salinity level in both tanks are 1.024 and I am using Reef Crystals from Aquarium Systems. What can I use to bring this level up to where it belongs? And what are the down side to running a low Mag level?

 

[reefrunner69]

Moved to Saltwater and Reef General Forum.

IMO, that is not that low. NSW mag is about 1200ppm. One of the theories about magnesium is that it is a buffer for your CA and ALK. If you are running a normal ALK and your CA refuses to raise to where it should be...you should test your Mag, it is most likely low and the opposite is also true. There is no doubt that Mag is important, otherwise it would not be found in such high concentration in Seawater. What you can use to raise it...There are many Magnesium supplaments on the market today, I used to use the one by Kent. If you'll go to www.ozreef.org there used to be a recipe for a DIY mag supplament that used epsom salt.

 

[EMS503]

Guess I should have added these levels Calcium 490 & Alk. mid 11s trying to lower the Alk. level This is the reason I tested the Mag level I was told this might be off.

 

[reefrunner69]

With a CA of 490 ppm, for your ALK to be in balance it would need to be 18.2 DKH, so it isn't high, it is actually low. I think the reason it is low is cause the CA is so high. I see no reason to maintain the CA above 450ppm, I shoot for 440ppm with a balanced alk of 11.2.

Here are a couple of calcs to hekp you figure what is in balance and how much of what is needed to raise levels to the desired level.

http://www.andy-hipkiss.co.uk/caalkcalc.htm

http://www.andy-hipkiss.co.uk/mgcalc.htm

http://www.andy-hipkiss.co.uk/cacalc.htm