Bubba Kushman
Well-Known Member
I have a friend that is using a Ebb and Flow set-up with rockwool blocks. The blocks look very wet and have algae all over them. The plants look healthy but they are starting to get tiny yellow spots on the lower leaves. Does the algae have anything to do with the problem or is that a K deficency? I told them I thought it was a K problem and to flush first then use a complete NPK fertilizer and add a little exra K. Then get block covers but I dont know what the algae will do to the roots. Do you need to clean the blocks first? If so what do you use? Any help appreciated!