dektos

Hi friendly reefers, I am planning on rescaping my tank and have bought some rocks. They have been cycling in a separate tank for the past 3 weeks and I have seen some fuzzy growth on the rocks and was hoping i could get some information on whether it is something to be concerned about. I have observed that they tend to grow in areas with higher flow and are spreading around the tank and glass. Don't want to introduce something into the tank that i will regret in the future and am fully willing to restart the cycling if sterilizing the rocks are necessary. Thanks so much for your help! A pic for reference is attached below