cause of bubbles from my millie?

[mysterybox]

About 2 months ago, I puchased 2 Tunze Stream 6000's w 7095 controller. I have just now got the water flow about right for all of my SPS's.
For the past few days, my small millie colony has 6 or 7 places where a small line of bubbles connected to a line of thread (mucus?, Zooxanthellae???????...no clue). The bubbles are small, and I think they form at or near polyp. Even in high flow the bubbles are staying on the millie (acro). They stay close to the coral and are nestled together. I pulled a string off yesterday which caused no problem. Otherwise, the millie appears to be doing very well.
Any ideas?

Params:
calc=430
Alk=10.6/3.77
trates= <1.00ppm
phos=< .024 (deltec)
temp=80

Thanks!
Ralph

[pepeinthenavy]

I wouldn't be too worried. Do you have micro-bubbles that enter the main tank?

[mysterybox]

yeah