What’s the difference between a saltwater pool and a freshwater pool? They both have chlorine in them, don’t they?
Yes, they do, but how they get the chlorine and maintain it is what makes all the difference. The results and the cost are different as well. First of all, let’s look at how they work.
These are the normal pools most people are familiar with. The water usually comes from your garden hose which means it’s fairly safe, to begin with. You manually add chlorine regularly, usually in the form of chlorine tabs or shock. The chlorine reacts with the freshwater to create something called hypochlorous acid, which in turn reacts with particulates and other contaminants in the water to neutralize them.
You also have to test the water’s pH levels and chlorine levels at least twice a week. Keeping the water balanced can occasionally be tricky, and may require a substantial commitment of time.
The initial setup doesn’t require any extra expense, but the chemicals for the pool can run anywhere from $300 to $1000 per year, depending on their price at any given time. Just like gasoline for your car, the price(s) can, and do, fluctuate.
Benefits of a Freshwater Pool
The benefit is that it’s a well-known type of swimming pool. The methods and means of maintaining a freshwater pool are well known, and the information is widely available. There aren’t going to be any surprises waiting to trap the unwary.
There is an additional piece of equipment saltwater pools need, over and above the usual pump and filtering equipment – a chlorine-generator. It works by passing a small electrical charge between two metal plates, separating the water into hydrogen and oxygen. Salt is added to the pool instead of chlorine, and it reacts with the hydrogen to create hypochlorous-acid, which is the same chemical created in a freshwater pool.
You need to test the water about once a week instead of twice, and you won’t have to shock it but a few times a year. Salt is very inexpensive, so you’re looking at $100 or less per year. You can even use non-iodized table salt in it if you want to. The generator has to run 18-24 hours a day so your electric bill will be higher.
Benefits of a Saltwater Pool
One primary benefits are that the overall maintenance requirements are very low. The generator keeps the chlorine levels very low, and very stable, for extended periods. Additionally, because the chlorine levels are kept so low, there isn’t the same chlorine odor around them as with a freshwater pool.
Saltwater is very “soft” in the way it feels. People with sensitive skin don’t have nearly as many problems in a saltwater pool as they might in a regular pool.
Chlorine and salt are both corrosive. In a freshwater pool, the chlorine levels are fairly high. If they get too high you could get some corrosion or scaling.
Saltwater pools still have chlorine in them, but at much lower levels. However, they have salt in them too. Salt is very harsh on everything it touches, but particularly on metal.
A good generator will keep the level at 4000 ppm (parts per million), which is below the level where people can taste it (about 6000 ppm). Nonetheless, salt is in the water in addition to the chlorine, so a saltwater pool will have a greater chance of corrosion than a freshwater one.
This is one area where freshwater pools definitely have the edge over saltwater ones.
Typically, a swimming pool needs about 2-4 ppm of chlorine. Chlorine evaporates rapidly so chlorine tablets, or tabs, are often highly concentrated, and have to be added regularly every week. This causes the chlorine levels to jump up and down erratically, thus increasing the amount of maintenance you have to perform.
Saltwater pools don’t suffer from the constant ups-and-downs of freshwater pools meaning less maintenance, less effort, and more enjoyment on your part.
Freshwater pools are a known quantity, so people tend to gravitate toward them. Saltwater pools, by contrast, are relatively unknown – although they really shouldn’t be – so people have a natural tendency to avoid them.
But over the long haul saltwater pools have an easier upkeep, and after you get past the initial expense, they are cheaper to maintain.