Is allgie on a drain supplying water to a cistern mad?
My friend lives with his parents. His mom posted a video of a French drain that supplies water to their cistern. Its a wide pvc pipe. I noticed some green (allgie) on the inside tip of the drain. Is that something to worry about? Surely there is already allgie in the stream where the water is coming from, so would the allgie on the pipe make much of a difference?