Hello, I have been using the BBB system for the last couple of years, but now I have a question about your preferences for filter type. My current sand filter needs to be replaced, but I'm not sure about replacing it with another sand filter or moving to a cartridge filter. My pool is an inground pool that is t-shaped and holds about 30000 gallons. I've heard the cartridge filters can be alot less maintenance, but would like to hear from actual owners. Thanks.