Pool Care 101



The two single most important factors in achieving good water quality are to add the correct amount of chlorine or other sanitizer daily and to maintain proper pH.

How to Maintain Proper Free Chlorine Levels

Make sure the free chlorine level of your pool never falls below 1.0ppm. Chlorine kills harmful bacteria and algae.

Shock Dose

Once a month during the peak swim season, it’s a good idea to superchlorinate the pool using a shock chlorine in order to bring the free chlorine up to 6-10ppm. This routine shock dose will help break down organic pollutants and chloramines.

Check pH Levels

To ensure that the chlorine is working effectively, the pH should be checked regularly and kept between 7.2 and 7.6.

Other Items to Watch

In addition to the key items listed above, there are a number of other levels to keep an eye on to ensure that your water is properly balanced:
Total Alkalinity – Proper pH can be hard to maintain if the water is not alkaline enough, and too much alkalinity can cause cloudiness and scaling
Calcium Hardness – Maintaining proper calcium hardness levels will help protect pool surfaces
Cyanuric Acid Stabilizer – If your pool uses stabilized chlorine donors, be sure to use enough stabilizer to control the amount of chlorine lost to sunlight. Too much stabilizer is also a problem, because it weakens the chlorine’s effectiveness.


Free Chlorine

Test daily, and more often in hot, sunny weather, when the pool is more likely in use). The free chlorine reading when using the DPD 1 test tablet should be 1.0–2.5ppm with unstabilized chlorine. If you’re using stabilized chlorines like dichlor (dichloroisocyanuric acid) and trichlor (trichloroisocyanuric acid), it should be up to 4–5ppm.

Dose rate

For dichlor: 125g per 15,000 gallons to raise free chlorine by 1ppm
For trichlor: Recharge the skimmer or feeder device with tablets and control chlorine levels by adjusting the water flow
For calcium hypochlorite: 100g per 15,000 gallons to raise the free chlorine by 1ppm
For sodium hypochlorite: 4/10 of a quart per 15,000 gallons to raise the free chlorine by 1 ppm


Once a month you may want to superchlorinate, preferably with an unstabilized chlorine like calcium hypochlorite or calcium hypochlorite to raise the free chlorine to 6–10ppm. Calculate the dose rate from the figures in the preceding section.

WARNING: Never mix different types of chlorine together before dosing, and do not allow them to make contact in concentrated form. If superchlorinating using the skimmer, be sure to remove any chlorine tablets first.