Magnesium Elevation

[JamieC]

Hello all. Looking for a quick opinion on my 65g mostly SPS (Acros) tank. I do weekly 10g water changes.

I have been using Reef Crystals without issue for 6 months or so. I know Reef Crystals gets a relatively bad wrap for consistency.

For 6 months my parameters have been pretty steady as follows:
Alk, 8.5
pH, 8.3
Salinity, 1.025
NO3, always battling to keep it up 2-3ppm
PO4, .05-.08
Ca, 450-460
Mg, 1340-1350

2 days ago, 1 day after a 10g water change, I noticed STN on my purple bonsai. I ran through the full gammet of testing and see that all is the same except my Mg...it's over 1500 (the max my AF test kit will register). I checked the expiration of my kit and it's good till 11/2021. I tested again and got the same result.

Everything else in the tank is still doing well, including my snails thankfully. Do you think the Mg jump triggered the STN? Should I be looking for any other problems as a result of the increase?

 

[Ding2daDong]

I'm not sure what the problem is but I don't think it's the elevated magnesium. Double check your SPS corals to make sure they're doing well. I like to really look at the bases, sometimes turning the lights off and looking with a flashlight can help see things better. Obviously trying to lower those nitrates would be something I'd suggest.

 

[JamieC]

Lower my nitrates less than 2 to 3? I thought we wanted some nitrates...