This is part one of a multi
part series about pool water chemistry. In part one I am going to talk about sanitizers and I promise to keep it as entertaining as I possibly can.
When it comes to sanitizers think of it like they type of fuel your car uses. Some cars use gasoline, some use diesel, some are all electric; the possibilities go on and on. It is the same thing for you pool’s sanitizer. You have all kinds of options chlorine, bromine, Biguanide, ionization and ozone.
Let’s start with the most common sanitizer chlorine. Chlorine is a very effective sanitizer that is found in all kinds of products today from household cleaners to your pool sanitizer and it is used extensively throughout the world. The only thing that kills faster than chlorine is ozone. The advantage chlorine has over ozone is that chlorine can be held in the water in residual but ozone cannot and this is a huge advantage. I will talk more about ozone in Pool School 102.
Many people who have salt generators don’t realize that they are using chlorine as their sanitizer; they mistakenly believe that they are using salt. Salt is an inert product and cannot sanitize their pool water, what they are doing with the device they have is converting salt (sodium chloride) into liquid chlorine (Sodium Hypochlorite) through an electrolysis process. The beauty of this system is that when the chlorine they created is done doing whatever it is suppose to do it reverts back into a usable form of salt and you run it through the conversion process all over again, a very efficient process.
The two other most common methods of adding chlorine to the pool are Stabilized Chlorine Tablets (both 3” and 1”) and Calcium Hypochlorite. Stabilized Chlorine Tablets have been the preferred method of sanitizing pools from the late 70’s to the mid 90’s when salt generators took over the position as the most popular method. The best way to add chlorine tablets is in an in-line feeder installed after the filter and heater (if you have one). Putting the chlorine tablets in the skimmer is not good for your whole filter system and it will shorten the life of your skimmer basket. The chlorine tablets contain a very strong oxidizer and will oxidize everything plastic and metal in the system and cause premature failure of many of you systems components. If you don’t have an in-line feeder the next best option is a chlorine floater but you will need to tie it off by the return jet where the water comes back into the pool because the chlorine tablets are erosion tablets and they need the water running over them to dissolve them. If you just let the floater float the tablets will only soak and they will not dissolve quickly enough to keep up with the chlorine demand in the pool water.
The other method, which harks back to the 1930’s, is using Calcium Hypochlorite. Every day you go out mix up some Calcium Hypochlorite and pour it in the pool. This system was fine for back in the days when there was no filter system and the water was stagnant. But by today’s standards this would be a major hassle and cause many water problems.
So the best choice for a chlorine sanitizing systems is by far a Salt Generator. Several key reasons for this are:
– Chlorine is one of the fastest sanitizers on the market today.
– As the Salt Generator is making chlorine it is actually shocking the pool water for you so it eliminates the need to routinely shock the pool water.
– If necessary you can go up to two weeks or more without making any adjustments to your pool water, because you have an unlimited supply of chlorine in your pool.
I want to go into a little more detail on the last statement. A salt generator will continue to produce chlorine as long as the unit is working and there is sufficient salt in the pool water. We recommend you check your pool weekly because during the summer your pH will usually need adjusting after a week. As the water-cools and you turn the operation of the Salt Generator down the pH will be less affected and you will not need to adjust the pH as often. Hence you can go longer without any chemical adjustments if you were out of town and did not have the ability to make adjustments on a weekly basis. We don’t recommend this but in a pinch it will work.
In the market today chlorine is the dominant sanitizer because it is effective and cost efficient compared to other methods of sanitizing the pool water.