Q. I have a question regarding fertilizing.  My husband used a fertilizer that stained our pavers and the bottom of our pool in spots. Do you know of a solution to remove those stains? A. The fertilizer most likely had iron sulfate in it. The spots would be dark reddish brown or brown. Muriatic acid would remove it. Be careful using it. Iron spray staining grape berries. Be careful spraying iron on fruit vines and trees that have fruit on them if you care about appearances.             If it is in the bottom of the pool and water is in the pool there is not much you can do about that unless the pool was empty. The bag should have warned you, hopefully, to use a drop spreader if it was for a lawn.