weird problem with my frogspawn

[CAT]

i'm hoping someone can id this.

i've had this frogspawn for a couple of years. in fact i've fragged it several times. a couple of weeks ago i noticed a weird growth on one of the heads though the head kept expanding. now, as you can see from the pic below, the 'growth' jumped from one head to another. the white tube is pretty solid -- it's an almost clear tube but covered with what looks like sand. since this coral is at the top of the tank, sand is not a possibility.

all i can figure is that some critter is digging it's way into the head of the coral and leaving the tube behind to travel in. is this a possibility? i've added some new corals in the last month though they seem to be fine so far.

i've now removed the 2 infected heads, used a coral dip and am hoping that this will solve the problem. any suggestions on what this is would be appreciated

 

[ahuxman58]

Ive had that type of problem also, but on a Millepora SPS i just kept getting rid of it every time I say it took about 3 or 4 times of this and it finally quit but the unknown animal did do some damage to my Millie, my guess its some kind of worm but do not know