I`ve had my Mag pumps a few years now. I have a mag 12 and a mag 9.5 and both are return pumps. About every 3 to 4 weeks I take them out and wash them out really good. I noticed here lately that my flow was not what it had been. I was washing out every week or so. Finally I bought some VHO
bulbs at the good doctors and went ahead and bought some new sponges for my mag pumps. The results were tremendous. Even though I was washing them out pretty regularly they were still getting clogged up. The difference now is like night and day. Just wanted to share.