1 goes up 1 goes down Grrrr...

I would also get the mag up first then work on the other two.
I also keep my mag at 1500, it seems in my experince to help keep the cal and alk more stable ,it is also believed that a higher mag chokes out unwanted algae.

There used to be a cheap fix for cal but then dow changed there processing of calcium chloride (drive way melt) which has lead to a bid debate of using it because of the bromide(i think thats the name of it) left in it,
You can order calcium chloride from buckreef or similar for cheap.

http://www.bulkreefsupply.com/Calcium,-Alkalinity-&-Magnesium-Calcium-Chloride/c1_2/index.html

also here is a article for mixing the alk, cal, and mag and how to do the proportions when mixing by Randy Holmes Farley
he goes over different recipes and it is very informative.
http://reefkeeping.com/issues/2006-02/rhf/index.php

 

Thank you very much...

 

Reiteration; Hello, the best way to go about this is to add the Epsom salt to raise the Mag about 60 ppm per day until you reach the desired target level. This will be trial and error. Now once you reach that level do not add anymore and check the Mag concentration after 2 days. This will tell you the "fall off" rate or how much your tank is using. If after 2 days your Mag is holding, go another 2 days and check it again. To properly dose you must determine when and how much to dose. As you start to raise your Mag and have raised it at least 100 ppm or so you then use the same method to determine your Calc and Alk dosing.

 

Unless you have a tankfull of demanding corals, you won't see Mag levels drop off unless you do water changes. I got my Mag up to the 1450 range, and it would stay there spot on until I did a water change and dilluted the Mag levels. Primarily the coral and coraline algea will consume your calcium and your (alkalinity) to form their calcium carbonate structure, and they'll also take in strontium.

 

Yes, that is basic, however I gave that criteria because, as usual we didn't get enough info from the poster.

 

What missing info from the poster might have bearing on the fact that magnesium typically doesn't fall over time?

 

I added 500g of epsom salts which raised my mag 180 from 1140 to 1320, and all is doing great if not looking better then before,

 

What other info did you need, even though amcarrig kindly pointed out that i answered my own question?