Alum is a white powdery flocculant that when circulated in your pool water quickly clumps all fine particles, including green algae, into particles large enough to sink to the bottom. This allows you to simply suck up your pool water to waste it.

You may have noticed that we state that we know of a “guaranteed” way to clean your pool water virtually overnight. We say this because every time we have used Alum to clean our pool it has worked perfectly and consistently. No other product we’ve tested has come close to matching Alum’s performance or consistency.

We obviously believe in this product. But, don’t just take our word for it. Alum has been used in water treatment for longer than we have, so there is a lot of information on the web for you to research. Pool supply retailers sell it, and you can even find it at Wal-Mart.

Because you have to vacuum your pool so it goes to waste every time you use the Alum to clean your pool water, you will only want to use the Alum when your normal cleaning routine is overwhelmed by green algae or cloudy water that doesn’t leaks. This is how we find out how effective Alum is. Our pool had a light green algae mist that we couldn’t get rid of. We tried hard to impact, we used whole bottles of Pool Water Clarifier and filtered 24 hours for days, nothing cleaned the pool water.

In total frustration we bought 10 pounds of Alum at Leslie’s Pool Supply. We add the Alum to the water in our pool at the end of the afternoon. The water in our pool turned milky white. We ran the filter for 2 hours and then turned it off as instructed. The next morning when we checked in, our pool water was cleaner than we had ever seen it. We were immediately convinced that nothing worked better than aluminum sulfate to clean contaminated pool water. We have used it many more times since then and it has worked perfectly every time.

“Guaranteed” “Works perfectly at all times” there must be a catch. Not really, what happens is that once you add the aluminum sulfate to the water and everything sinks to the bottom of the pool, you have to vacuum it up so it goes to waste.

If you use cartridge filters to filter your pool water, you don’t want to use Alum in your pool. This product is not for you.

The alum will clog the cartridge filter immediately, and once it clogs the cartridge filter, you will have to clean the filter to remove the alum. This can be a nightmare. We don’t want to sell you a quick cure for green algae only to burden you with a worse problem later. You have to vacuum to remove the alum from the bottom of your pool. So if the pool filter you use to filter your water allows you to filter to waste aluminum sulfate, this is for you. We have seen several YouTube videos that do a good job of showing you how to vacuum your pool alum.

If your pool water is so green that you swear you can shut it off, Alum will clean your water in 24 hours. If the green algae is so light and fine that it goes through the filter and back into the pool, Alum will clean the water in 24 hours. If your pool is cloudy and the filtering does nothing to clean your pool, Alum will clean your water in 24 hours. We “guarantee” it.