Adjusting the Total Alkalinity in a Swimming Pool

Adjusting the Total Alkalinity in your Swimming Pool

It is vital to get the total alkalinity right. The total alkalinity (TA) is how much alkaline substances are in your swimming pool. The alkalinity controls the pH, which in turn controls the effectiveness of the chlorine. The total alkalinity (TA) is how much alkaline substances are in your swimming pool. We want this to be 80-120 parts per million (ppm). Having the alkalinity within this range keeps the pH from fluctuating.

If the total alkalinity is too low it will try to rob alkaline substances from your concrete walls or any metal parts, can stain the walls and floor of the pool, turn the water green, cause burning eyes and cause the pH to move around as we discussed earlier.

If the total alkalinity is too high, the water will become cloudy, chlorine will not work, and test kits will show that you constantly need to add acid to lower your fluctuating pH.

To raise the level of the total alkalinity, use sodium bicarbonate. Lucky for you, you probably already have some lying around as this is just regular old baking soda. No need to go buy expensive pool chemicals that are the exact same thing. Look at the ingredients to make sure. Baking soda (sodium bicarbonate) is the only chemical known by mankind to raise the total alkalinity without messing up the pH. Go to your local grocery store and pick up the recommended amount then pour it around the pool at a rate of about two to three pounds per day. If your alkalinity is really really low, this may take a little while but adding any more than that at a time is just a waste of money.

To lower the total alkalinity, we use either a dry or liquid acid. The same kind you would use to lower the pH but we add it to the pool in a little different manner. Turn the pump off and allow the water to settle and then add the dissolved dry acid or liquid (muriatic acid) to the deep end of the pool. It is recommended to wait three days between treatments requiring over one gallon but I have not noticed that results are any different if you just separate the treatments by one day.

In conclusion, you must get your total alkalinity correct before anything is going to go your way in the battle of keeping a crystal clear swimming pool. Think of it as the king of swimming pool chemistry.