What Pool Chemicals Cannot Be Added at the Same Time

Pool chemicals should be added one at a time, whether you’re balancing the water, shocking the pool, or adding a specialty chemical. For most water balance changes, the pump needs to run for at least four hours before you can add another chemical or retest the water. What Pool Chemicals Cannot Be Added At the Same Time?

Most common swimming pool chemicals are incompatible with each other & shouldn’t be mixed or stored together. Mixing organic chlorinating agents for pools & spas like (trichloroisocyanuric acid) & inorganic chlorinating agents (sodium hypochlorite) can lead to adverse reactions & chlorine gas release.

Never let pool chemicals contact each other. A harmful chemical reaction could happen, even when outside of the pool. Chlorine mixed with any other chemical or foreign substance can emit toxic gases, erupt in flames, explode, or all of the above. Always store chemicals in properly sealed secure containers in an area that’s cool, dry, well-ventilated, and away from kids.


What Pool Chemicals Cannot Be Added At the Same Time


 How Long Does it Take for Pool Chemicals to Work?

How fast Pool Chemicals work is dependent on the size of the pool, the pumping rate of the filter system & how much chemical is needed.
Alkalinity takes 6-8 hrs. or a full turnover of the pool water
PH is 4-6 hours.
Shock Chlorine- at least 30 min.
Cyanuric Acid- one full turnover……………………………………… Read more


Some chemicals for your swimming pool are incompatible and should be stored separately from each other and never mixed together for any reason. Chemicals should be added one at a time and in series with others. Perhaps most important of all never add chlorine and muriatic acid or Dry Acid together, whether outside the pool or in it.

This creates a dangerous toxic gas that can have severe health consequences if inhaled. Don’t ever shock the pool immediately after adding acid to the water. Also, never add acid to the pool when chlorine levels are high, such as after you’ve shocked the pool. Wait at least 4 hours or more between applications.

  • Never mix different types of chlorine together. Mixing incompatible pool chemicals can cause a dangerous chemical fire, explosion, or release of toxic fumes. In fact, mixing any type of organic and inorganic chlorine compounds meaning a stabilized and unstabilized chlorine can cause a bad reaction.
  • Store stabilized organic chlorine (dichlor shock and trichlor tablets) separately from your unstabilized inorganic chlorine (cal-hypo shock and liquid chlorine), both during pool application and while in storage. When shocking the pool, never put chlorine into the skimmers, especially if you have an inline or offline chlorine tablet feeder.
  • If using a floating tablet dispenser, pour the shock far away from the floating dispenser, or just remove it from the pool until the shock has enough time to dissolve. Don’t pour the shock right next to or on top of the dispenser.
  • Never mix new chemicals and old chemical
  • Improper storage of pool chemicals can cause chemicals to react with each other. Storing oxidizers (such as calcium hypochlorite) alongside acids (such as muriatic acid) is particularly dangerous, as these two chemicals can react on contact to produce chlorine gas.
  • Always read the chemical label


How Long Do You Wait Between Adding Pool Chemicals?

All pool chemicals take their own time to mix and dissolve when added to pool water then changing the chemistry of the pool water but it all depends on the chemical’s active ingredients or strength and the volume ……………………………………. Read more


Adding a clarifier that contains aluminum sulfate alongside a sequestering agent  HEDP can also result in cloudy pool water. Other ways to ensure safe pool chemical use include avoiding adding chlorine shocks to pool water containing high concentrations of metals or enzyme-based products.

*Other precautions include avoiding concurrent use of hardness increasers such as calcium chloride along with alkalinity increasers that contain sodium bicarbonate which can make your pool water cloudy and cause scale to form on your pool surfaces and equipment.


Can I add Alkalinity, and Shock at the Same Time?

No, Never add chemicals at the same time, whether you’re balancing the H2O, shocking the pool, or adding a specialty chemical. For most H2O balance changes, the pump needs to run for at least 4 hrs, or long enough for the pump to turn over the pool before you can add …………………………………………………….. Read more


JimGalloway Author/Editor


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