I wouldn't pour it in the skimmer, it's some thick stuff!! Mix it up in a 5 gallon bucket of pool water and pour it around the pool. After you pour it out, you will have to cut the jug with a box knife and rinse the rest of it out into a bucket. It so thick, a lot of it will stay in the jug if you dont rinse it clean. It's expensive, but it's instant CYA. Check the jug. One jug should add 30 ppm to 10,000 gallons of water.