If you're wanting to clean water minerals from the ceramic or glass, use vinegar. Don't let the straight vinegar get in the pump parts because there is no way of knowing what problems it might cause. But if you use vinegar, it will slowly dissolve the minerals. Watch for the foaming bubbles that come off when the vinegar is poured. Use a soft nylon brush to remove anything that is loose, rinse the parts you're cleaning, then do it all again. It may take several applications to get it clean, but it also shouldn't harm any of the ceramic parts.