Cub Cadet Collectors dot com

hey guys I know I got a lot of questions but I have a 128 cub with the 44a deck I just replaced both belts for the deck I got a cub cadet dealer look up the pto belt and got it and put it on but it seems to be loose how do I know when its tight right now if you engage deck it squeals for a bit then stops then randomly it will squeal so I think the belt is loose here is a pic of my mule drive how do I know when it is tight and not over tight ?