My better late than never response
I had a DE filter, but it was getting old, and kept leaking DE into my pool. I had changed all the grids, and it still leaked.
Got tired of this, and changed to a Pentair Clean & Clear Plus Cartridge Filter 520 Sq about a year ago.
My pool is covered (just through away my old, disintegrating safety cover and put on a solar cover), and I use a robot type pool cleaner, so the filter doesn't have to work very hard. I have not had to clean it yet, so I don't know how hard it is. But so far I'm happy with the cartridge.
troublefreepool is a great resource. I use bleach/chlorine for my pool, and it works great. The real trick is adding borax or boric acid to your pool. It keeps algae from growing. I don't add chlorine to my pool during the winter, and with it covered and the boric acid I never get algae. At the start of the year I have to shock with with a bunch of chlorine, then its good to go.
Jon
I don't think you need to worry about your pool floating up in so cal. That only happens where there is ground water, and we have no water anywhere. But an empty pool really isn't safe. If someone falls in and hurts themselves it would probably be a nasty lawsuit.
Randy