Troubleshooting orange euphyllia

[sage23]

I've had my fair share of successes with the traditional green Euphyllia over the years, but the orange variants just don't seem to be my cup of tea. I'm talking orange torch and frogspawn specifically - they start off strong for a month or so, but then slowly decline no matter where I place them in the tank.

I've tried positioning them right next to other Euphyllia types, but nothing seems to work. One thing that might be worth noting is that this started happening after I began dosing magnesium to raise my levels. I used to run around 1100, but I've been adding 1 cup of Mag (Sulfate, crystal type) every two days to bump it up to 1300.

My current params are:
Ca - 400
Alk - 8.7
MG - 1300
SG - 1.025

A few other things that might be relevant - I've been dealing with an ongoing brown slime issue on my rocks, which I'm pretty sure is bacterial. I've taken out my BP reactor and switched to running carbon full-time, and I've been doing 35g water changes each week while scrubbing the rocks to try and get rid of it. I also recently started dosing CA/ALK with pumps, starting at 25ml a day.

[floralix]

Orange Euphyllias seem to be on the delicate side, I've noticed a big difference in growth rate compared to my greens and purples - the oranges grow much slower. I'm thinking of adding T5s to see if I can promote better growth, currently they're all under custom LED fixtures. They're holding well under these params though.

My tank is 24" with mid and low level placement, low flow, just a light sway here and there. I use RC Salt, and my current params are:
SG 1.026, CA 480, Alk 9.8-10.5, Mag 1350, Po4 0.04.

[sage23]

Thanks for the input. I'm still unsure what did my frogspawn in - was it the rearranged scape or the added MG. 53ppm doesn't seem excessive, but I guess it's possible. There's still a bit of flesh on it, but I've seen this before and it doesn't usually end well.