What is the cheapest cleaning solution for a cartridge swimming pool filter?

Spraying your garden hose on it full blast is the absolute best...and cheapest. I've tried other chemicals, pretty useless.I blast them once then the next time I pitch them. Hum, what a waste of money on the above answer and person. You should get 3 to 5 years out of your filter cartridges. There is a product on the market that is specifically for cartridge filters "cartridge filter cleaner". Add water to a clean 30 gal plastic trash can, add the quart or litre, mix slightly, hose off your grids fairly well, put them in the solution and leave overnight. Remove each unit and hose off with adequate water pressure and install in the filter. You might want to buy spare cartridges for the time when you just do not have the time to clean those dirt ones. Your grids will come out nearly new looking. Yes, just plain water is the cheapest but it will not get the body oils or suntan lotion or other goo. Lets say in a given situation that you only get 3 to 4 months out of the filters before they are so dirty that they will no longer filter well. That is 4 sets of cartridges every year times $XXX dollars. So if you have 3 to 4 cartridges inside your filter - hum, that is a tidy sum of money out of your pocket that was or is totally unnecessary.