Can I Add Alkalinity and Shock at the Same Time

Changing the Total alkalinity in the chemistry of your pool water is a slow process slower than any other chemical adjustment process that you will make if you own a swimming pool inground or aboveground the one thing I learned after 30 years of owning an inground pool. Never add chemicals too close together. 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 shock chlorine or retest the H2O.

Follow these directions for adding chemicals to your swimming pool whether it’s inground or small aboveground patience is needed especially when you balancing alkalinity readings that are too low or too high.


Can I Add Alkalinity And Shock at the Same Time


If you can take anything from these articles then remember that you should never mix any chemicals together and that any pool chemicals should always be added one at a time and never stored together. Wait a while before adding any shock chlorine to your swimming pool Look at pool water levels.

I recommend that for any Balancing chemical added to the pool water be patient and try to wait for the pool water to be turned over. Most pool pumps are sized and should be able to turn over the pool water completely 2-4 times a day.

You can find out the pool pumping rate from the specs on the filtering system. First, find out the volume of your pool and how much water it holds. Then calculate the pumping rate of the pool pump without the timers on.


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 of your pool, and how much change is needed ………………………………………………… Read more 


*For a square or rectangle-shaped pool, the formula is length x width x Average depth = volume x 7.5 gals. (in a cubic foot) will give you how many gallons your pool holds.

A 1.5 HP pump would give you a flow rate of approximately 90 gallons per minute which would circulate this pool just fine 

if you run the pool 8 hours per day, you need to “turn over” the water once per day. If you take 24,000 gallons divided by 8 hours, that means you need to circulate 3000 gallons per hour or 50 gallons per minute.

So a pool that is 20 ft. long and 18 ft. wide and has an average depth of 6 ft = 2160 cu ft. x 7.5 = 16,200 gallons in your pool. If your 1.5 hp pool pump pulls approximately 90 gals/per min 16,200 divided by 90 =180/60 mins in an hour= 3+ hours.

In about 3 hours your pool is turned over which means any chemical added to your swimming pool is mixed between 3 and 4 hrs. You should wait around 4 hours to retest Alkalinity before moving forward. If this doesn’t make sense to you use a Pool Volume Calculator


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 ………………………………………………………………….. Read more

How Long After Alkalinity Can I Shock


Total Alkalinity in a swimming pool is always the longest time to get results. This is because the results depend on the size of your pool, the active ingredient in the chemical, and the target you are looking for the chemistry has to completely change in the pool water. When adding an acid like muriatic acid the results will even fluctuate and become unstable for some time.

You need to wait even longer for the pool to turn over. I will add acid or an alkaline chemical at night and retest in the morning for a more stable reading with the filter running. Then add shock chlorine.

If you add acid this will lower both the total alkalinity and pH. Check the total alkalinity last. Add stabilizer and chlorine afterward. Add them one at a time waiting 10-30 mins between different chemicals (except for pool shock or cal-hypo – wait 24 hours).

Granular chlorine, pH, and alkalinity-adjusting chemicals can be dissolved first in a bucket of water. But not at the same time of course.


 In What Order Do I Add Chemicals to My Pool?

  • Alkalinity(80-140 ppm) wait time 4-8 hrs.
  • Retest TA
  • pH (7.2 -7.6 ) wait time 30 min.
  • Retest pH
  • Calcium Hardness-(200–400 ppm) wait time-30 min.
  • Cyanuric Acid-(25-50 ppm) wait time 30 min.
  • Shock the Pool-10 ppm wait time-4 hrs.
  • Algaecide after shock wait time-5 days ……………………………………….. Read more 



JimGalloway Author/Editor


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