Spider Web thread-like coming from Cup Coral?

[bonjour2]

I got a small Cup Coral in my tank.Near the polyps opening, there is this spiderweb thread stuff drifting ard above the cup coral , whenever I try to use the PH to blow them off , the cup coral will form new threads again.

Anybody knows what this is ? Or anybody with Cup Coral that does the same thing?

Water Parameters:

Temp : 27 degree celcius

Salinity: 1.020

Hardness(Carbonate): 10dkh

Calcium : 400ppm

NH3: 0PPM

NO2: 0PPM

NO3: 25ppm

PO4:0.2ppm

MG :1020ppm

PH:8.3

[Golden Tooth]

Leave where there is medium flow n monitor it. Should be fine.

[RockyBoy]

There is an animal and live in the stone which would cast a sticky net out. Then it pull back the net to eat whatever it has caught. I've got one in my chritmas tree coral.