+ Equipment questions can be hard to answer, without exact information. By far the easiest way for you to give us exact info, is with pictures. Try to get BOTH overall shots, and details. If possible include an *in-focus* photos of all equipment labels. You can either mail the pictures to poolforum@gmail.com OR post them directly using the [IMG][/IMG] tags to show the image on Photobucket, Webshots, Picasa, Flickr, or other non-porn photo host.

Pictures of the plaster would help. Color and detailed stain description would, as well. SPECIFIC info about your test results AS WELL AS your test method, would also be relevant.