Adding Alum to clarify the water


New member
Aug 12, 2019
Our pool (100,000 liter (28,000 gal) lap pool) was getting cloudy, so we added some alum to get the cloudiness to precipitate or coagulate so it would drop to the bottom where we could vacuum it up. We did this a year ago very successfully, but this time it has taken 3 days and still isn't clear.

Anyone have any experience with that?


Gold Supporter
Jul 2, 2018
Austin, TX
Experts will chime in soon. It’s not recommended to put any kind of metals or pool store potions in your pool.

You probably have algae and need to SLAM. You should read pool school and get a good test kit from or the Taylor 2006c