I am amazed at how fast this Algae grew! It literally popped up overnight on me. I did some reading and it sounds like it will not be a problem, but I wanted to kill it anyways. It stinks!

I decided to put a panda paper over the blocks of rockwool and cut holes for the seedling stems to come out. This way the algae cant get light and will die.

Here is a pic:

Seedlings Grow Algae on Rockwool