is a bacteria .
Also referred to as red , red / green slime algae .
High nutrients , poor lights are the biggest cause .
I just read a article in I love reefing . Com
There are 1000's of different species ,
I had a problem awhile ago and found my cause .
I was using municipal water ,
Phosphates , nitrate and other nutrients are the cause .
I started using RODI
water and the cayno disappeared .
Check your water quality ,
You may not get positive readings for phosphates but they are there .