Putty For Frags Growing Algae??

[Nano Reef Q]

Ok..not saying it grows the algae but I have noticed that everywhere I have put a frag & used nonpotable putty I have algae growth...it's odd. Frags were placed different times from 3 diff sources.

Anyone come across this?

Attached pics of one item where it's happening. My snails eat away what's growing on most of the other frags but I felt this particular area w/my fingers & its a little loose/soft so maybe that hinders them from feeding on this spot.

 

[jsker]

What are you nitrates and phosphates something is feed the green hair algae.