Pool School

Matt Giovanisci: 00:00

Everyone, and welcome to Pool School by Swim University, where we help you keep your pool clean and clear all year. My name is Matt, and I'm the founder of swimuniversity.com. And on this episode, we're talking about clearing up a green pool in 24 hours without algaecide. Let's dive in. Real quick, if you want more help taking care of your pool, be sure to grab our free pool care cheat sheet at swimu.com/cheat.

Matt Giovanisci: 00:36

This is the fastest way to clear up a green pool, and it's not with algaecide. It's called the shock and flock method. And it's a 1 2 punch that kills algae quickly, clumps it together so that you can easily remove it from your pool. Now while algaecide works well to prevent algae from growing in the first place, it's actually less expensive or less effective and more expensive if you've already have a green pool. So if you wanna go from green to clean quickly, then it's time to put away the algaecide, and we just use the shock and flock method instead.

Matt Giovanisci: 01:11

So first, why can't you just use algaecide to kill algae? So don't get me wrong. Algaecide does kill algae. Okay? It's great at preventing algae from growing in the first place, and it works really well when when it comes to treating early stage algae growth.

Matt Giovanisci: 01:28

So that's, like, when you're just having algae starting to appear. So algaecide is a good insurance policy to add regularly to your pool, especially if you have chronic algae issues. But if you're dealing with really green water and algae that has really gotten out of hand, algaecide really isn't the best option. Actually, a much quicker and cheaper way to kill larger algae blooms is with a highly concentrated dose of chlorine. And that's where the shock comes in.

Matt Giovanisci: 01:58

So how do you do the shock and flock method to clear up a green pool? Well, shocking is the act of highly it's it's you're adding a highly concentrated dose of chlorine to your pool, and that boost of chlorine kills contaminants and it kills algae. 2 of the most common ways to shock a pool are with something called cal hypo or calcium hypochlorite shock, which is usually usually comes in bags, and liquid chlorine. Now I said, Cal Hypo Shock is sold in 1 pound bags, and it's more concentrated than liquid chlorine. So most times, just shocking your pool and running your filter will be enough to kill algae.

Matt Giovanisci: 02:38

But if you wanna clear up your green water in half the time, then you can use both shock and flock, which is also known as flocculent. You might also see it labeled Alum, a l u m. That does the same thing. So using both of these speeds up the process. Now while the shock kills the algae, the flock coagulates, which basically means groups particles together, those little particles that are making your water cloudy and and that's and end up being dead algae.

Matt Giovanisci: 03:11

And it makes them much easier to remove from your pool. So as the algae dies, it'll clump together and settle on the pool floor, thanks to the flock. The only downside to this method is that you'll need to remove those clumped together particles with a manual vacuum. And flocculants should not go through your filter system. That means you'll need a multi port valve on your filter with a waste setting and a recirculate setting for this process.

Matt Giovanisci: 03:39

Okay. So here's how to use the shock and flock method, Simple as that. So before starting, make sure that your filter is cleaned and backwashed. You'll also need a few few supplies like test strips. You'll need a pool brush, a 5 gallon bucket, flocculent, and either Cal Hypo Shock or liquid chlorine.

Matt Giovanisci: 04:01

Now the first step is to raise your pool's water level about 2 to 3 inches above whatever it normally is, which should be about the middle of your skimmer. So it should be almost close to the top of your skimmer. You'll be vacuuming out this water later, so this helps to make sure that the water level doesn't drop below the skimmer, and then your pump starts pulling in air. Step number 2 is you wanna test and adjust your pH because this will help the shock work better. It should be a little on the lower side because shock, when you add it, is gonna slightly raise your pH.

Matt Giovanisci: 04:34

Step number 3 is is shocking the water. So depending on how green your water is, you'll wanna add a double or triple dose of shock. Some shocks work best when it's pre dissolved in a bucket of water before adding it to your pool. We recommend doing this, but just make sure that your filter is running and it's on recirculate and it'll help it dissolve and disperse. And if any of that leftover shock particles land on your pool floor, just use a brush and brush it up and it should dissolve.

Matt Giovanisci: 05:02

Step number 4 is you're gonna add your Flocculant. You wanna wait at least 30 minutes after shocking your pool so that you know the shock is fully dissolved. Right? Then you add the flocculant and just follow the directions on the back of whatever type of flocculent you choose to buy. Again, it's it's there it goes by so many names, but you're looking for f l o c, and that's just called Floc.

Matt Giovanisci: 05:27

It's spelled flocculant. That's the full word, flocculant. Right? And again, it comes in many forms. If you're going to the store, just ask for it.

Matt Giovanisci: 05:39

If you're online, just look for the word flock. In fact, we sell a flock called Fast Flock. It's pretty easy. Step number 5 is you're gonna run the pump for 2 hours to circulate the shock and the flock. So you're gonna make sure that your filter is set to recirculate and not filter.

Matt Giovanisci: 05:56

Okay. You don't want the flocculent to get caught inside your filter before it has a chance to work. Step number 6 is you're gonna brush your pool. So while the chemicals circulate, brush the walls pool And then once you're done, you wanna keep your brush head in the pool overnight so that the shock can kill any lingering algae spores on the brush. Because if you don't do that and you just take your brush out, you let it dry, and then you go and stick it back in the pool when your pool is clean, you're introducing those algae spores back into the water.

Matt Giovanisci: 06:35

Kind of defeats the purpose. Step number 7 is you're gonna let the pool sit for at least 8 hours. Better yet, let it just sit overnight. The longer you let it sit, the easier this is gonna be. So make sure that you're com make sure the pool is completely still so that the flocculent can work, clump everything together, and sink everything to the bottom.

Matt Giovanisci: 06:55

So that means you wanna turn off any water features, any automatic timers, anything that's gonna kick your filter system back on. Step number 8 is then your at the next day, you're gonna vacuum out the algae. The water should be much bluer and you should see a cloud of dead algae sitting at the bottom of your pool. It's actually pretty cool looking. Using a manual vacuum, okay, not an automatic vacuum.

Matt Giovanisci: 07:20

Automatic vacuums are not gonna work here. They're just gonna blow the cloud all over your pool, and it's gonna you're gonna have to wait for it to resettle. So you need to use a manual vacuum and you wanna set your filter system, your your multi port valve, you wanna turn that to waste and slowly vacuum out that algae cloud or that dead algae cloud. And don't move too quickly because the more you move, it's just gonna disturb the cloud, and it's gonna disturb the flock, and it's gonna you're gonna have to wait for it to resettle. Alright.

Matt Giovanisci: 07:50

Step number 9, is then you're gonna skim, filter and rebalance. So use a skimmer net to remove any last floating bits of algae particles, and then you're gonna run your filter as normal. Finally, you're gonna retest your water and adjust your alkalinity, your pH, and chlorine as needed. And that's it. If you need to refill your pool, make sure you do that before you test and add those chemicals.

Matt Giovanisci: 08:12

Now remember, if you need more help with pool maintenance, grab our free pool care cheat sheet at swimu.com/cheatcheat. And if you found this episode helpful, subscribe because you're gonna get more pool maintenance tips just like this one on your favorite podcasting app. And when you do, please leave us a review because your support will help more pool owners just like you find this show. That's it. Thanks again, and happy swimming.