Use HIGH grade tubing
Make sure you use a high grade, below the water line approved hose and double clamp it at every fitting. I have read many stories of 22 owners finding their boats on the bottom because of this hose failing. The drains exit through the bottom of the hull, below the waterline, if you crack this hose your boat will sink. DO NOT use the cheap corrugated blidge hose. Here is a link to the type of hose I used: