A DIY Guide to Opening Up a Swimming Pool

After a long winter, a pool opening is an event worth celebrating, but you have to do it right, or the celebration could end with skin rashes and other symptoms of unhealthy water. The pool has been sitting idly for several months full of stagnant water, and the water has to be treated. You know this, of course, and you'll be shocking the water with a ton of chlorine, so just be sure the celebration doesn't start prematurely, which would be before the chlorine levels have fallen into the safe zone.

You'll also want to prepare yourself for the pool opening by gearing up with personal protective equipment, including goggles, rubber gloves and a respirator. You'll need this safety equipment to protect you from nasty pool chemicals, such as muriatic acid and pool chlorine, which send over 4,000 people to emergency rooms each year, according to the Centers for Disease Control and Prevention. It's just as important for you to be safe as it is for you to provide a safe experience for pool users.

During the multistep pool opening procedure, you'll be removing the cover; cleaning the pool; restarting the pool pump, filter system and — if you have a saltwater pool — the chlorinator; and balancing the chemistry of the pool water before you shock it, which is the last step. Each step in the procedure requires the preparation of one or more of the preceding steps, so it's important to follow all the steps in sequence. And though in-ground pools and above-ground pools are different sizes and are made of different materials, the opening procedure is essentially the same.

Unless your pool has an automatic pool cover, you're going to need help because most pool covers are too large for one person to handle. Before you do anything, you need to remove the water from the cover to keep it from getting in the pool. You can use a pool cover rake, but it's a lot easier to use a pool cover pump or just a regular sump pump. You'll also want to sweep any debris off the cover before you remove it.

To remove the cover, you have to lift — not drag — it off the pool to avoid tearing it, which is why you'll be glad to have a helper. Lay it flat in the yard and let it dry out. Then, before folding it and putting it away, sprinkle some talc or alkalinity increaser on one side to prevent mold and mildew. If the cover is torn or damaged, now is the time to buy a new one so you'll be ready when winter rolls around again.

With the pool cover gone, you'll have your first look at the pool water, and it isn't likely to be a pretty sight. It will be discolored and possibly full of debris. Don't worry — you're about to deal with that, and this procedure will give you a good start.

You're going to shock the pool water with chlorine to get rid of all that grunge you saw when you removed the cover, but before you do that, you have to test the water for alkalinity, pH and calcium hardness, in that order. If you don't do this, the chlorine you add to the water will be less effective than it should be. The best way to test the water is to take a sample to your local pool outlet, but you can also do it yourself with a test kit or test strips.

The pool water is balanced when these levels are achieved:

• Total alkalinity: between 80 and 120 parts per million (ppm)
• pH: between 7.2 and 7.6
• Calcium hardness: between 200 and 400 ppm
  

Pool water tends to become acidic over the winter as it sits stagnant, and the best way to raise it, assuming the total alkalinity also has to go up, is to add baking soda, but if the alkalinity is already high, raise the pH with soda ash, which has less effect on alkalinity. If the pH is too high, you can lower it with muriatic acid or dry acid (sodium bisulfate), and if the calcium hardness is low, add calcium hardness increaser.

Now that you've established a balance in the swimming pool chemicals, the last thing you need to do is to introduce a whole lot of chlorine at once, which will take care of the algae and bacteria discoloring the water once and for all. Typical free chlorine levels in healthy pool water are between 1 and 3 ppm, but you're going to add enough chlorine shock to raise the level to 5 ppm or even higher. This will obviously make the water unsuitable for swimming, so don't plan on using the pool until the chlorine concentration has fallen to a safe level, which will take a day or more.

Pool shock doesn't work if the chlorine breaks down too quickly, and since this happens in direct sunlight, the best time to add shock is in the early evening so the chemical has the entire night to work. It's also a good idea to use a product that includes a stabilizer to forestall the UV degradation of chlorine. The proper dosage is typically 1 pound of shock per 10,000 gallons of pool water but check the instructions on the label just to be sure. You might consider double shocking — as many pool pros recommend for a pool opening — which means doubling the recommended dosage.

You need to be wearing your protective gear when you shock the pool. The product comes in granules, and you can simply walk around the edge of the pool and pour them directly into the water, or you can dissolve them with water in a 5-gallon bucket and pour the solution into the pool. If you use the bucket method, do not use the bucket to mix any other cleaning or sanitizing products, as combining chlorine with other chemicals can release dangerous fumes or even cause an explosion. Turn on the pool pump after shocking and leave it on for at least 24 hours to be sure the sanitizer circulates throughout the pool system.

If all goes well, the pool water should be clear enough on the next day to allow you to see all the debris on the bottom that you missed when you did the preliminary pool cleaning, so you'll want to spend some time vacuuming it out. You can also use the vacuum to remove fuzzy growth from the sides of the pool, although there shouldn't be much to remove if the shock was effective. However, if the water had been particularly dirty, this residue as well as cloudiness in the water may be due to the carcasses of dead microbes, and since you can't kill the microbes twice, you may need to add flocculant to the water to remove them.

Pool flocculant (floc), which is a supercharged type of pool clarifier, works by binding onto the microscopic particles, causing them to coagulate and drop to the bottom of the pool. It may take two or three days for this process to complete when using pool clarifier but only a couple of hours if you use floc, after which you remove the residue from the bottom of the pool by vacuuming. Because the water you vacuum out has to go to waste, you'll have to top up the water level in the pool, and you'll have to clean the pool filter. If you have a cartridge filter, opt for pool clarifier instead of floc.

Sometimes, you can't get rid of the greenish or brownish tinge in the water, which means that algae are still active, and that's a bad sign because they will just multiply if you don't do something. That something is to add pool algicide, and if your pool is in full sun, you should have a few bottles of this on hand for periodic treatments throughout the summer. Follow the instructions on the label to ensure you use this product properly and that it gives the intended results.