I purchase 4 inch purple in last 3 month and it look good until a last week when i got new coral and my current salinity is 1.022 to 1.023 but i have increasing a salinity to 1.025 according to coral requirement, one of their limb look like crumbed but it still moving around, how to save him, should i lower a salinity back to current salinity and amputate a infected limb from spread, i don't want to lose him