Seed flow Sensor Needed

Hey all.. Im fairly new to this forum. So to introduce myself. My name is Matt, I live in Manitoba Canada and I'm a farmer. So we farm lots of acreage and I run an Bourgoult air seeder which is 60 feet wide and has a 700 bushel tank. It is fairly automated, but what it doesn't have are seed blockage sensors on each hose. I'm wondering if it were possible to use an infra-red sensor or some kind of proximity sensor that detects if there are seeds flowing through the hose or if the pipe is blocked. Could anyone give me any suggestions or has anyone tried anything like that? The hoses are about 7/8" in diameter. Thank in advance Matt