Oops! Don't let the wife dose

So I messed up, and dosed magnesium based on an old test kit. I dosed enough to get it up by 60, and now the coralline looks like it's starting to bleach. I ordered a new kit, but is there someone in the Riverton area who would let me use their mag test if I bring over a water sample?

I can test / help in sandy if you didn't get it taken care of already...

Yes. My first test was 980. This is a new setup, and all the test kits were super old (aka not used), so I expected it to be low. After dosing 13oz of magnesium sulfate crystals according to the calculator instructions, the level went up to 1040. Right after I dosed, our Alk and Calcium tests arrived, and tested decently (420 and 7.7/2.73), so the magnesium must be off.

I admit, it was my first time dosing. Steve has always done the dosing with previous tanks. Now I'm seeing people saying to read about mag, calcium, and alk for a month until I understand it well, and then start dosing.

We did a 15% water change last night, and it looks stable, but the coralline is looking sad, and one small sps frag bleached yesterday morning. I think we'll take a sample over to the Aquarium for a $2 mag test to cover until we get ours. (Steve doesn't want to put anyone out.)

Any advice?

While you are at it, might as well have them test Alk and Ca to verify your results. I also would be happy to do all 3 tests for free, but I'm even further away from you than Nick and Badfinger.
A reef can handle quite high Mg levels, but if you added 3 oz short of a pound of Epsom Salt all at once, it probably shocked and stressed things. Keep the SPS frag in the tank. Bleached SPS often recover.

Please don't think our offers are an inconvenience. We do this for other hobbyist because it's been done for us when we had the need. You know, Pay it forward. It's also part of the friendly social nature of this group. It's the WMAS legacy. We have fun visiting each other and learn a lot from each other while we enjoy each others tanks.

Aloha,
Mark
808-345-1049 call/text/visit anytime

Maybe I'm not understanding the calculator correctly. When I use the BRS calculator, say I have 100 gallons (110 tank plus sump), and put in numbers to raise is by 100ppm, it tells me 13.1 oz of mag sulfate crystals. Is 13.1 oz for the crystals or the mixed solution?

BRS calculator gives values based off of mixed solution not dry crystals. I would bet your Mg is way high as well. Probably closer to the 1600-1800 range. That could definitely cause some shock and bleaching in corals for sure. I lost a plating monti to a Mg dosing error that increased it more than 300ppm in one day. Not fun. Hope your larger system handles it better.

If you dont have all test kits I would be happy to test Mg , Ca, Alk , PO4 and sg for free , you not far from me.