I love my Mr. Landscaper system and have recommended it to many others. We have had ours for about 3 yrs. Usually about twice a year, a few of them stop putting out the spray that they originally did. After cleaning, blowing, etc., they still don't work, so we buy the whole purple and black assembly with the diaphragm included (2 for $4.39) and all is perfect again. That does get expensive and Lowes does not sell the the filters only, but they should. Going through this again this year prompted me to look you up on line and I am happy that I can buy the diaphragms only for a lessor price. I just wish I had known this 3 yrs. ago! I could have saved alot of money.