You've received some good advice so far. I'll add this, take the air pressure down on the tires first, then mount the chains, then repressurize. Chains end up tight without additional tensioners. Its usually good for a link's worth of tension.
AND, for cheaper chain prices check with your local TSCor other farm supply place or truck stop, and buy truck tire chains from Peerless or other manufacturers. They are smaller links so not quite as aggressive. They also fit where larger ones won't if you have close fenders or three-pt links, etc. The smaller links are also quite a bit lighter for lifting and installing. For a flat profiled tire like a turf, you really bounce around with a large tire chain, so the smaller links give a nicer ride. Turfs with truck tire chains is a great combo. Mine cost less than $80 for the rear tires (<$80 for both). BTW, take your tire dimensions with you 'cause they wont have a chart for your tractor, and take both the metric and inch size numbers, for whatever their chart says. You may have to cut off a few links when your putting them on the first time, borrow or buy a big bolt cutter, or use your 4" angle grinder or hacksaw. Cut them to fit perfectly, your tires will never grow, it makes it easier to fit every year if there are no extra links, no decisions.