Calcium hydroxide works well, just turn off the flow (or at least get it down to a minimum). Mix the hydroxide into a thick paste (like you would for aiptasia) and use a syringe to coat the coral. Allow 20 minutes and then turn on the pumps. Being sure to watch the clumps of hydroxide so that they don't lant on any other coral.
So, you would recommend Calcium hydroxide vs Sodium hydroxide for the coral? I used Calcium hydroxide in the past for Aptasia then switched to Sodium hydroxide because it took a much smaller amount to kill them, basically immediately. I am talking only a drop in the mouth and they dissolved.
Are you able to create a paste with sodium hydroxide? I don't think you can. And I wouldn't risk sodium hydroxide because of how much more potent it is.
I was mainly stating to use it as a prying mechanism if your not saving the coral just chisel a chunk til you can see base rock then try and chisel a lip off of it.....insert chisel under lip and try and pry it off....idk its what i have done
I ended up making a Sodium Hydroxide solution with 62ml of RODI with 1tsp of Sodium Hydroxide in a small jar. Poured a small amount in a small glass bowl and added a small amount of Calcium Hydroxide to give it some color so I could see what I was covering. With return pump and Vortech's turned off, I covered the encrusting part of the coral with approximately 3-4ml of solution. After 15min I syphoned out a majority of the solution along with the dissolving flesh of the coral. Be aware that it will leave the area of the rock discolored. When I turned the pumps back on, some solution that did not syphon out that was crystalized blew around the tank for a few minutes until it was no longer visible. I did not see any increase in PH but then again my total water volume at the time was 255gal.
