Swimming Pool Start-Up Procedures from National Plasters Council

If you’re a pool builder or owner looking to apply a new plaster finish, it’s important that you know the ins-and-outs of a plaster startup procedure—these startup guidelines are essential to protecting the pool and prolonging the life of the pool finish. In this article we’ll cover the critical steps to filling the pool with water for the first time, as well as the 28-day startup procedure that follows.

Normally this is the responsibility of the remodeling company or builder, who will need to follow the guidelines to maintain the warranty on the pool finish, but pool owners should also understand the process they are paying for.

Download the "NPC Pool Interior Finish Disclosure" here

NPC Pool Interior Finish Disclosure

What is a pool finish startup procedure?

A startup procedure is the 28-day process of caring for a new pool plaster finish after the pool is filled with water. During this time, you’ll need to test your water regularly, maintain the chemical balance, brush the pool to remove plaster dust, and avoid using automated equipment.

Pool plaster will immediately start hydrating when mixed, and 86% of the cement in the plaster will cure within the first 28 days. This is why timely filling and dedicated startup maintenance is critical to any new pool plaster project.

What you will need

  • A good test kit that will test for pH, Total Alkalinity, Calcium Hardness, Cyanuric Acid, and Chlorine.
  • Good Quality Pole, Net, and Brush.
  • LSI Adjustment Charts. These charts help you follow the Langelier Saturation Index (LSI) method. See the attached PDF for LSI info. Using the LSI method is a more precise way to test and balance water and it is critical to a startup procedure. It uses single targets for water balance rather than “old school” ideal ranges, which are falling out of favor in the pool industry.
  • Chemicals: Water, Muriatic Acid, Sodium Bicarbonate, Calcium Hardness Increaser, Sequestering Agents, Chlorine Products, and Stabilizer.

Before You Get Started

  • It’s VITAL to perform each step in this guide. Do not skip around. Download the PDF for a printable startup card.
  • NEVER mix water into chemicals. Always mix chemicals with water.
  • Don’t shock the pool for the first 30 days.
  • Don’t swim until the water is balanced.
  • Do NOT use a pool heater until all plaster dust has been removed from the pool. This can typically be accomplished between day 4 and day 10.
  • Do NOT use these devices until AFTER the 28 days startup is complete. They may damage the new finish or get clogged due to plaster dust:
    • Wheeled Devices
    • Automated cleaning systems—built-in or robotic
    • Chemical Feeders OTHER than Oxidation Reduction Potential (ORP) and pH Controllers
    • Salt-water generators (Waiting up to 6 weeks to add salt may be beneficial)

Fill Day Preparation

The Fill day precedes the 28-day startup procedure. It can take between 18 and 36 hours to fill the pool. Once you begin filling the pool, do not stop or it will leave a distinct line where you stop filling. If you are worried about the pool over-flowing at night when you are sleeping, just turn the water supply down so that the pool continues to fill more slowly.

Keep these things in mind before you begin:

  • Make sure the filtration equipment is operational.
  • Remove all floor return heads and directional eyeballs. (If appropriate for your geographical area)
  • Test your fill water first. Record your results!
  • When filling the pool with a garden hose, wrap a clean rag around the end so it doesn’t come in direct contact with the pool finish. You can also attach a water bottle to the end of the hose, so it floats. (see details below)
  • Do not let your pool finish dry out before it is submerged. Fill the pool up to the tile line/skimmer. Stopping early can leave a ring at the stopping point.
  • If you have a spa, do not let it flow into the pool.
  • Do not allow people or pets in the pool.

Fill Day

  1. Fill the pool to the middle of the skimmer or specified water level without interruption as rapidly as possible with clean, drinkable water to help prevent a bowl ring. Soften the impact of the water with these techniques:
    • Place a clean cloth on the end of the hose and then position the hose in the deepest area of the pool to prevent damage to the surface material. You can also attach a water bottle so it floats.
    • If a water truck is required, 24 inches (60 cm) of water should be placed at the deepest area for a water cushion.
  2. At no time should any person or pets be allowed in the pool during the fill. A newly plastered pool finish is highly susceptible to footprints or pawprints.
    • It is recommended that you do not swim in the pool until the water is properly balanced and sanitized, according to LSI.
    • Do not allow any external sources of water to enter the pool. Any water left on the surface prior to being filled can leave stains.
  3. Test fill water for pH, alkalinity, calcium hardness and metals.
      •Record your test results throughout the process. There are LSI Apps that you can download to track the process and perform LSI calculations.
  4. Start the filtration system immediately when the pool is full to the middle of the skimmer or specified water level.

1st Day

**NEVER add water to chemicals! Always add chemicals to water prior to adding them to the pool. A 5-gallon bucket is great for pre-diluting chemicals.**

  1. Test fill water for pH, alkalinity, calcium hardness, and metals. Record your results.
  2. High Alkalinity should be adjusted to 80 ppm using pre-diluted Muriatic Acid (31% - 33% Hydrochloric Acid). Always pre-dulite the acid by adding it to a five gallon (19 L) bucket of pool water.
  3. Low alkalinity should be adjusted to 80 ppm using sodium bicarbonate (baking soda).
  4. pH should be reduced to between 7.2 and 7.6 by adding pre-diluted Muriatic Acid if the alkalinity is already 80-100 ppm.
  5. Brush the entire pool surface, from the top of the walls down, starting at the shallow-end and ending at the deep-end. Brush thoroughly twice per day to remove all plaster dust. Brushing your pool finish at least twice a day is one of the best things you can do to maintain the gorgeous appearance of a pool finish. Remember, wheeled devices should not be used in the pool until after 28 days.
  6. Although optional, it is highly recommended to pre-dilute and add a quality sequestering agent using the recommended initial start-up dosage and then the recommended maintenance dosage per the sequestering agent’s manufacturer. This is cheap insurance against metal staining.
  7. Operate filtration system continuously for a minimum of 72 hours.
  8. DO NOT add chlorine for 48 hours. DO NOT turn on pool heater until there is no plaster dust in the pool.

2nd Day

  1. Test pH, Alkalinity and Calcium Hardness and repeat steps of 1st day except for step 6.
  2. Once the alkalinity is adjusted to 70 ppm and the pH is adjusted to 7.2 to 7.6, then adjust calcium hardness levels to a minimum of 150 ppm. (CAUTION: Adjustments requiring more than 20 lb. of CaCl^2 should be pre-diluted and added in 10lb increments – morning and afternoon.)
  3. Brush the entire pool surface thoroughly at least twice daily to remove all plaster dust. Again, routine brushing is critical to a long-lasting, beautiful pool finish.

3rd Day

  1. Test pH, Alkalinity and Calcium Hardness and repeat 1st day, Steps 1 through 5.
  2. Pre-diluted chlorine may now be added to achieve 1.5 to 3 ppm. No Salt should be added for 28 days.
  3. Brush the entire pool surface thoroughly at least twice daily to remove all plaster dust.

4th through 28th Day

  1. Test pH, Carbonate Alkalinity and Calcium Hardness and repeat 1st day, Steps 1 through 5, for the first 14 days. Carbonate or Corrected Alkalinity is Total Alkalinity – 1/3 Cyanuric Acid Reading.
  2. After the 4th Day, calcium levels should be adjusted slowly over the 28-day period not to exceed 200 ppm.
  3. After the 4th day, adjust cyanuric acid levels to 30 to 50 ppm based on the primary sanitizer of the pool (pre-dissolve and add through the skimmer).
  4. On the 7th day, if there is any plaster dust remaining – remove it using a brush pool vacuum.

After 28 Days – Daily Water Chemistry

After the first 28 days, you continue to maintain your water balance through testing and adjustments. The Langelier Saturation Index (LSI) must be maintained between 0.0 and +0.3 for day-to-day maintenance after the initial start-up procedure has been completed. Please see the attached PDF for charts and ranges and download an LSI app. Another great tool is a floating water monitor, such as the ¬pHin, which will measure your pool’s temperature, sanitizer, and pH levels.

This will help to reduce the likelihood of problems with the pool surface. Disregarding these LSI parameters promotes leaching, etching and discoloration on the negative (-) side and scaling and discoloration on the positive (+) side.


These procedures are sound technical practices in the industry and are advisory and non-binding. The National Plasters Council does not regulate, control, or monitor the acts of its members or others in terms of conformance to any of the guidelines, recommendations, or other information contained in these technical procedures.

Purchase "Taking Care of Your Pool DVD" from the National Plasterers Council here.

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PRODUCT INTENDED FOR USE IN ACCORDANCE WITH STANDARDS ESTABLISHED BY THE NATIONAL PLASTERERS COUNCIL. FINISH MUST BE APPLIED CONSISTENT WITH APPLICABLE BATCH FORMULA CARDS. NOT TO BE USED ABOVE THE WATER LINE. PROPER WATER CHEMISTRY BALANCE REQUIRED AT ALL TIMES. OTHER LIMITATIONS MAY APPLY. SEE LIMITED WARRANTY FOR DETAILS & ADDITIONAL PRODUCT APPLICATION INSTRUCTIONS. Due to a variety of influences, your actual pool finish & water color may differ from the images shown in this brochure. Images & color samples are featured for inspiration & to show a range of design ideas for your NPT pool finish. Always check a sample of the actual product prior to purchase or installation. Some finishes may include seashells which cannot be guaranteed against degradation or loss of color. www.nptpool.com

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