Help

[beashay]

I have a big problem notice saturday night that my frogspawn had dropped a little peice of tenticle.. I moved him cause where it dropped was near my kenya tree.. I checked all testing.. everything fine.. 0 on ammonia, nitrate, nitrite, phosphate, ph at 8.2 calcium at 480 showed normal range 1.7-2.8 Sunday got up checked on my babies and my kenya looked to have a spot in her branch that looked discolored and dried looking.. I assumed maybe a peice of the frogspawn must of landed there and burnt her.. well not far from her is a colt coral that sunday I also noticed had a area that looked like it was loosing tissue. I put in a dose of iodine by sunday night the colt had a brownish film in the area that has tissue lose... I decided to cut the infected area off to keep from getting the rest of the coral.. this morning the colt was laying on the rock but its polys were extended.. I get home from work tonight and the colt is covered in the browning film.. I also noticed that my other colt on the other side of a 55 gallon tank also had this film on it, I did a ten percent water change.. added new carbon and now looking I see a peice of this brown stuff on my kenya tree.. my frogspawn that has two heads.. one im assuming where the peices were dropping looks shriveled up and I can see some skelton.. the other head.. where the mouth is is bubbled up.. I dont know what the heck is going on.. I do have some idoine on site.. should I did the kenya tree.. the one colt looks like a lost cause.. I have a group of xenia in there they are not affected.. my mushrooms.. not affected all zoos not affected.. I havent changed anything or added anything in weeks.. also have a waving hand, star polys.. they seems fine..55 gallon tank.. coralife 48 inch 265 watt pcs ten gallon hob refugium. canister filter. any advice would be greatly appreciated