To elaborate more on Josh's recollection of my horror story of Mg dosing and bad test kits.
I had brand new Elos test kits from BRS. Dated from early the month before i bought them.
At first my Mg tested at 1050 from the elos and 1100 from the Salifert. Being new to actually having to dose Mg I considered this quite large spread normal to be honest. So days of dosing turned into weeks of dosing, even after calling ESV to offer some advise as to why my Mg would not raise past 1200. He suggested that I increase the dose to almost 180ml a day, which i was only dosing 90 (seems it was my fault for not interpreting the directions correctly). At any rate, increase the Mg to 1350 according to the first Elos test kit. Checked my SG (was stable the entire time at 1.025 except for one weekend I left town for a day and came back it was a little over the 1.026 mark). Nothing huge in my opinion. Anyway, some of my Zoas started to look a bit off color, some were closed, and some were just fine. So i tested and retested consistently hitting around 1300. So, I got to thinking, there has to be something wrong here. Tested a batch of fresh saltwater Mg and it was a bit low, around 1200.
At this point my zoa garden started looking a bit thinner than usual. My thinking was something bad was about to go down.
Took some water to Josh and Mg was just at 1780 or around that after 2 tests. So immediately got a different test kit, and low and behold 1750 from the new Elos test kit.
It took me a while to bring the Mg down, but basically I did a >10% WC every 3 days (10 Gallons on 120 Gallon total volume system), with quality salt (Tropic Marin) keeping a very close eye on everything from SG to NO3 to CA etc. Making sure NOTHING took huge dips or hikes during this process.
If i were you, I would grab a new kit. Take the new kit, the old kit and some samples of fresh salt water and current tank water test them both, and then test them a friends kit that is known to be a good kit. As much as they are low quality, the API Mg test kits can provide a good stable mediator with top quality kits like Elos or Salifert or Hanna etc. do <u>small</u> WC's every 3 days until you get the Mg in line, and then keep on top of it for dosing until you find the right dosing for your tanks needs. Also, during this time, KEEP YOUR HANDS OUT OF THE TANK AS MUCH AS POSSIBLE!! Anything on your hands can make sick or dying corals go into overdrive and kill them faster. If you must get some out of your tank or flip it over or anything of the like, short of stacking fallen rocks, get one of those plant clippers from petsmart or one of those old people grabber things you see on commercials from target or walmart or something. Keep an eye on salt creep and anything else that might contribute to even more harm to your already unstable tank.
This entire process took about a month and a half to fix entirely. But can take less than a week to go from stable to FUBAR.
If you have any questions feel free to PM me. Im in Tyler, so i cant physically help but i can at least share some information in the details i left out.
