organism
code monkey
I top off by removing 10lt and I use the hose method to slowly pour 11lt back into the tank once every week, I get my saltwater from my LFS supplier who uses crystallized salt mix.
Just to clear up, you don't dose any new freshwater into your tank to make up for evaporation?
I'll be ringing up few of our LFS and see if they have the service to do the job because I don't have the equipment nor would I know where to cut, but since you are the second person to suggest I frag the dead skeleton I will go my way to see that this is done, the other two mouths look healthy on the Euphyllia and it would be a right shame to lose them.
You don't need to be fragging it for it to survive, it's dying from water quality issues so that's only going to stress it further. A dip in a bucket of tankwater with some Lugol's iodine wouldn't hurt, but you need to make sure it's getting flow and that you're fixing your water parameters.
You need to consider buying a refractometer with 35 PPT calibration fluid, your own ro/di unit, an auto top-off unit, and some pickling lime for mixing 1 Tbs per 3 gallons of ro/di top-off water.