Pool Water Alkalinity Vs Ph

Another word for basic is alkaline.

Pool water alkalinity vs ph. A value of 7 to 14 is considered basic with 14 being the greatest base activity. Ph is a measure of acidity in water whereas alkalinity measures the ability of the water to neutralize acid. Here s what i learned. Hot tub water chemicals can be confusing and i ve often wondered what s the difference between ph and alkalinity in a pool or hot tub.

Your pool water ph and alkalinity can affect disinfection by chlorine. 1996 ohio short course. To correct the ph add something alkaline like soda ash or sodium bicarbonate. However this is not to be confused with total alkalinity.

If the ph is low the pool is too acidic. When ph is high the pool is too alkaline. So while they interact. Ph and total alkalinity are not the same but can be influenced by each other.

In fact the ph of the water does not dictate the ph of the growing medium but in fact it is the alkalinity of the water source that influences the ph of the growing medium. However even with high ph a pool could still be sanitary with good levels of free chlorine and clear water from effective filtration. H 2 o co 2 h 2 co 3. At a ph of 7 4 to 7 6 your pool water is non corrosive and comfortable to swim in and free chlorine sanitizes your pool water with a high degree of efficacy.

Most pool owners use sada ash aka sodium carbonate to raise alkalinity level in pool water. Nelson substrate ph and water quality. The ideal ph level for your pool water is slightly alkaline at 7 4 to 7 6 to clarify i m talking about alkaline on the ph scale not total alkalinity this lean towards alkaline is intentional because it s where chlorine works best as well as being easy on your skin and your pool equipment. The ideal total alkalinity level is 80 to 120 ppm.

You could add several pounds of 8 3ph sodium bicarb and make the same ph impact if you added a much smaller amount of 11 6 ph soda ash. Chlorine is very slow to react at high ph levels and can be over 50 inactive at ph levels over 8 2. It is clear that the ph of the water and the alkalinity are not the same. Since co 2 controls the ph of the water you can either add co 2 directly to lower ph or you can use acid to convert bicarbonate alkalinity into carbonic acid h 2 co 3 which is just dissolved co 2.

Sodium carbonate has a very big impact in increasing ph levels because it comes with high ph of 11 3 to 11 6 which is tool high if you only wanted to raise your ta levels and not ph. That can be fixed by adding co2 or muriatic acid.