Mag Question?

So I have been on top of my water. Check every week. I just got a mag test kit as I seen that I needed it. I tested and it was way low 780. I used a red sea test. Now where I get confused is all my other water test come out good. I always thought if the calcium and the DKH is good then the mag was good also:-/ I have a sump and euroreef skimmer run charcoal got plenty of water movement in the tank. I always keep up on my water changes and cleaning I am just anal about my tank even the outside glass LOL.

Now here is my water testing.

Ph-8.3
amon-0
nitrites-0
phosp-0
nitrates-.05 (gotta do a water change)
Calcium-460
temp-78
dkh-11
mag-780

Now I am wondering if maybe the test was old as where I live there is not that many people who do saltwater and the store maybe had it on the shelf for awhile? I don't want to start raising my mag until I am pretty sure I need to. So can someone shed some light on this for me?

 

I doubt that, that is correct. I bet that your test kit is expired or you did it wrong. Buy a new test kit. Luna

 

Most local fish stores will test your water for you so you might try that.
Mag is not to dangerous to raise so I would suggest making a small change upward and retest. Some people run mag way up between 1500 and higher and claim no problems. I try to keep mine around 1300.
Also if you know someone else with a marine tank you could test their water with your kit and see how it reads.

 

Not sure if you've read this article, pharmrjohn shared it with me on another thread.
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com
Based on your other numbers being right, I would agree that your Mg test is probably wrong and that it should be re-tested.

 

Hi, you have nothing in your profile to help, however, if you have Coral and other creatures that use Mag. then you will more than likely need to dose, how much and how often will be determined by the rate of consumption, which you will have to monitor. Salt mixes, for the most part, do not replenish Mag. to the proper levels. I dose Tech M and my tank uses Calc. and Mag. so much that I dose 5 out of 7 days. Do yourself a favor and get the Salifert Mag. test, it is one of the most accurate out there.

 

If it was the first test with a new kit ? Take the vial and rinse it well in tap water then in the tanks saltwater and re test the tanks Mag. Levels I used Red sea for yrs and I keep one here now to double check my Salifert they also make junk kits from time to time and I see really weird test or sudden jump or decline I double test again then use the red sea..

Oh and at 780 its more then possible to have the Ca and Dkh to proper levels .. Thats not a true indicator of Mag Levels all the time..