How to Treat Pool Water for the First Time

Reviewed by Andrada Simion, Master of Science in Chemistry

Opening a pool for the first time takes a fair amount of preparation, but the moment you first dive into that cool water on a hot day will make it all worth it. Here are some tips to help you get your pool going.

  1. Clean Your Pool Before You Begin
    Dirt, leaves, and other debris can collect in an empty pool, so be sure to clear them out before you start filling it with water. The more you’re able to clean out in the beginning, the less work you and your filter will have to do later on in the process.
  2. Install Any Pool Accessories
    If you haven’t already done so, install any ladders, diving boards, step rails, or slides. Once you’ve filled your pool with water, it will be much more difficult to put in these accessories.
  3. Wear Safety Gear
    You’ll be dealing with potentially dangerous chemicals, so wearing personal protective equipment like gloves, safety glasses, and respirators can limit your exposure to them. Thousands of people each year are treated by medical personnel for pool chemical-related injuries, so taking the proper precautions is very important.
  4. Prepare Your Pool Chemicals In Advance
    Be sure you have all the chemicals you’ll need to treat your pool, including:
  • Clarifier
  • Sequestering agent
  • Calcium, Alkalinity, and pH increasers
  • Shock treatment
  • Chlorine tablets or granules
  • Stabilizer (cyanuric acid)
  • Algaecide
  1. Fill & Filter
    Begin by filling your pool halfway, adding in the sequestering agent at this time. Use a skimmer to clean out any additional large debris as necessary. When you’re done, turn on your filter and let it run for 12 to 24 hours before filling it up completely.
  2. Test The Water After Filling
    Test the water for pH balance, calcium hardness, alkalinity concentration, and any heavy metals that can cause stains. You’ll need to know how much to adjust these levels once you begin adding the chemicals. You can purchase testing strips or kits in order to do this.
  3. Give Your Pool A Shock Treatment And Balance The Water
    A shock treatment will get rid of chloramines (combined chlorine) and kill any algae, bacteria, or other organic waste in the water. Balance the pH levels to 7.2-7.4, the alkalinity to 80-120 ppm, and the calcium hardness to 200-400 ppm.
  4. Add In Chlorine, Stabilizer, And Algaecide
    Your chlorine level should be about 1-3 ppm and the cyanuric acid level from the stabilizer about 20-50 ppm. The stabilizer will help the chlorine last longer and work more efficiently. Add the algaecide to protect your pool from algae buildup and keep it looking clean and clear.
  5. Let Your Filter Run Again
    Once all your chemicals have been added, allow your filter to run and circulate the water for another 24 hours. You want to do this so the chemicals will be mixed in and evenly distributed throughout the water, as well as getting rid of any remaining debris.
  6. Store Chemicals Somewhere Safe
    When you put your pool chemicals away, put them where they’ll be out of reach of children or animals. Leave them in their original packaging so you know what’s what and can refer back to any instructions, as well as keep an eye on their expiration date. Make sure they’re closed up tight and store them somewhere dry and cool.
  7. Put In Any Final Touches
    Set up lounge chairs or bring out any toys and floats you want to use. If you have a childproof fence, make sure that’s been set up and can be securely locked. Now that your pool is filled with water and chemicals, you don’t want your children or pets falling in when you’re not around.
  8. Enjoy!
    Your pool is now ready to use! Jump in and enjoy the fruits of your labor. While you’ll have to continue to maintain the water, the hard part is over. Keep it clean and test the water often. Add chemicals as needed to adjust their levels until they’re balanced.