I am changing out a cartridge filter for a sand filter on an above ground pool. Someone is coming to install the filter this week. Looking at pictures of sand filters I always see the pumps with the discharge vertical out of the top of the pump. My pump has a horizontal discharge for the cartridge filter. Does that matter? The installer didn't say anything about the pump but I might have heard him say he will have to do a 90 degree elbow off the discharge. Any issues with that?