Hi everybody! I've been thinking on switching from sand to cartridge because my filter is about 25 years old and about to die. I have a in ground pool with two return lines. My question, would the return flow back to the pool be as strong with the cartridge type filter, or would i see a increase, or decrease in the flow. Right now i have a 3/4 hp pump and a 24" sand filter and plan to use the same pump on the cartridge filter for the time being. The sand filter i now have is rated at 60 gpm and the cartridge filter i plan to buy is rated 75 gpm. I'm thinking the flow would be about the same, or maybe a slight increase. The pool is a 18' X 36', and the deep part is 8 feet. I'm guessing about 30,000 gallons of water. The cartridge filter i plan to buy is a Hayward Star Clear Plus C-751.