I'm trying to find filter cartridges for an Intex Easy-Set 15' x 3' inflatable pool, but our local Canadian Tire retailers are all out. Does anyone have any ideas? The cartridge I need is their Type A cartridge - 4 1/8 inches wide by 8 1/8 inches high. I can order them directly from Intex, but I'm not sure yet how long they'll take to arrive as we're in Canada and Intex is based in the U.S. It's kind of urgent as we just got the pool without realizing we should have gotten a supply of filter cartridges, and they only last two weeks.