Anyone know where a good place to buy replacement filters online?
Yes, I found the best deal on ebay, and they carry some cleaner parts for Maytronics and others. The cart filters are half of what you pay elsewhere. I recently got a set, and they are genuine, OEM/BNIB carts for my M5. Scroll down on the page, and she has a list for the specific carts listed by cleaner.
Dolphin/Maytronics Filters