Salt Water vs Chlorine Pools
Chlorine tablets have been the traditional means for pool cleanliness for over 50 years. They became the traditional standard because the technology and available disinfectant has made these pools easier to clean and maintain. They rely on chlorine tablets to clean and disinfect the pool water from germs, bacteria and algae. The tablets are dispersed into either an external chemical feeder that’s installed near your pool equipment or an in-pool floating disbursement device.
The most convenient way to dispense the chlorine tablets into your pool is with an external automatic feeder. These feed systems range around $50-$250. When the pump is running, water will flow over the tablets, slowly dissolving the chlorine and dispersing it through the pool water. Altering the dispense rate to keep your chlorine levels within optimal range is simple to do with the dial on the chemical feeder. The dial simply adjusts the amount of water flowing over the tablets which, in turn, changes the rate the tablets are dissolved and released into the pool water.
Another chlorine disbursement system is a floating dispenser that releases chlorine into your pool from the tablets. These range from about $10-$30. These can work great in smaller pools but aren’t the ideal choice for larger pools because the tablets are floating on the surface of the water without a lot of water flowing over them to encourage dissolvement.
Feeder choice doesn’t really play a factor into how much chlorine you’ll need for your pool. Your pool chemical feeder will hold enough tablets that it will only need to be refilled every 1-3 weeks. The active ingredient in chlorine tablets is usually trichlor-S-triazinetrione which typically is 99% of the tablet, leaving very little filler ingredients to be added. Most tablets are stabilized to prevent chlorine loss due to the sun’s UV Rays although you can purchase non-stabilized tablets as well. There are even tablets available with additional ingredients to prevent scaling, soften the water, and last even longer than traditional chlorine tablets. Most pools will require 16 ounces or two 3” chlorine tablets per 10,000 gallons of pool water a week to maintain proper chlorine levels. A single 50-pound bucket of 3” tablets will typically contain 100 tablets. Bather load, weather and other factors can alter your chlorine requirements.
Chlorine tablets are commonly used on all pool types such as cement, plaster, painted, pebble, vinyl and fiberglass, whether they are residential or commercial pools. Pools using chlorine tablets are easy to maintain and maintain proper water balance. For this reason they are highly popular among commercial pools that have to maintain water balance within strict guidelines or they will be shut down until properly balanced.
In short, the pros and cons of using chlorine tablets are:
- Easy to maintain proper chlorine levels
- Stabilized to prevent chlorine loss due to UVA rays
- Excellent for all pool types and residential or commercial pools
- You have to fill your chlorine dispenser every 1 to 3 weeks with tablets and the buckets can be heavy
- Have to buy and store the chlorine tablets
- The stabilizer in the chlorine tablets can build-up over time in the pool and may require you to partially drain and refill the pool to get the levels back into the proper range.
Chlorine Generators, AKA salt pools or salt generators, on the other hand, have been gaining popularity over the past 20-30 years. When a chlorine generator is added to a pool, salt is poured into the pool and may need to be brushed until it’s been dissolved. The salt generator itself is made of parallel titanium plates that electrolyze the dissolved salt to produce chlorine.
This means that the pool water is not chlorine free. The same levels of chlorine are needed to maintain a pool using a chlorine generator as a pool using chlorine tablets. The average recommended range for a residential pool is between 1-3 parts per million (ppm) of chlorine. A chlorine generator’s job is to produce chlorine from the salt in the water. The process is comparable to how chlorine tablets are manufactured in a factory.
Altering chlorine production levels is done with an adjustable dial or buttons on a control panel that enable you to change chlorine production rate in a similar way as a chemical feeder. Instead of changing the water flow over a tablet, the production is changed by changing the frequency and duration the chlorine generator cell is on for. There are some higher end units that will make those adjustments automatically but they aren’t commonly used due to higher cost, setup and long term maintenance.
Chlorine generators come in a wide range of pricing and available features. To choose the best model for your pool, you need to consider the size of your pool, the amount of chlorine you’ll need to maintain proper levels, and what other features you would like it to have. They range between about $500-$3500 and usually include the power center/control panel and cell. The power center will typically last 5-10 years and the cell will usually need replacing every 2-5 years depending on model and frequency of use. Some pool owners have managed to operate their pools for up to 6-7 years on a single cell but this is rare for any model.
The most frequently praised quality of a pool using a chlorine generator is how soft the water feels. The water is soft due to the salt in the water. Most chlorine generators require your salt to be maintained between 2500-4500 ppm. For example, a 15,000 gallon pool will need about 425 pounds of salt when filling your pool or adding salt for the first time to achieve a salinity level of 3400 ppm. This level is low enough that your pool will only have the faintest taste of salt and won’t be high enough to irritate your eyes. The salt can also help prevent your skin from drying out when getting in or out of the pool. Think of it as swimming in contact solution. The ocean, by comparison, is a little over 10 times as salty.
Chlorine Generator Pros and Cons:
- No need to buy and store chlorine tablets
- Salt provides a soft feel on the skin
- Easily adjust chlorine production rate
- High upfront cost and replacement cell cost
- Must test and maintain proper salt and stabilizer levels
- Regularly adding salt and the salt bags are heavy
Maintaining a pool with a chlorine generator isn’t much different than a pool using chlorine tablets. We will focus a little more on the aspects of maintaining a pool with a chlorine generator than chlorine tabs as there is more misconception on the subject.
As mentioned earlier, a chlorine generator simply produces chlorine. This means you will still need to make sure your pool water is balanced and maintain proper levels of alkalinity, pH, and calcium hardness. The chlorine generator doesn’t do this for you or self-regulate these levels contrary to some information out there. Both types of pools also need to be shocked regularly, usually every other week or more often depending on bather load and other factors.
The chlorine produced by a generator doesn’t contain any stabilizer (cyanuric acid), so that will need to be added separately and kept between 30-50 ppm. When there isn’t any stabilizer in the water, the generator has to work much harder to maintain proper chlorine levels which leads to a shorter life of the chlorine cell.
Salt levels play a key role in the effectiveness of your chlorine generator. Too much or too little salt can cause the generator to stop producing chlorine. High salt can only be removed by partially draining and refilling the pool until the salt levels are where they need to be. High salt levels can cause damage to pool equipment and metal components as it’s corrosive.
Pools with chlorine generators can also have problems maintaining proper pH levels as the pH in salt pools will gradually creep higher than the recommended range of 7.2 to 7.8 in most cases and need to be adjusted on at least a weekly basis. This problem is the main reason commercial pools tend to use chlorine tablets instead of generators as they have to shut down their pools if they exceed pH levels above 7.8 and can’t reopen until pH is within proper range. A common solution for this problem is to install an automatic pH dosing system that will self-regulate the pH by automatically dispensing muriatic acid as needed. However, these pH dosing systems can get expensive. They range from the basic models starting around $600 to elaborate systems up to $5000.
Cost is another factor to consider before you decide between tablets or generators. It’s hard to say who the clear winner is between the two as for which is cheaper. For tablets, most pools will go through 1 or 2 buckets per year with a cost typically between $100-$175. A chlorine generator has an upfront cost of $500-$3500, though the most popular and commonly used units usually range $900-$1200, and a cell usually lasts between 2-5 years with a replacement cost of $400-$700. There are some cheaper cells out there in the $300 range but they tend to have a shorter cell life and produce less chlorine than higher end models. The power center for you chlorine generators will range from $300 to $500 and need to be replaced as they go out and as with any electronic device there are circuit boards and sensors that may need to be replaced and if you can’t diagnose and repair the device yourself there will be service charges for a professional to handle that for you.
Both pools will need to maintain the same level of total alkalinity, pH, and total hardness. Those costs are minimal but it’s important to account for the extra needs for pH decreaser or muriatic acid in a salt water pool. Salt pools also need salt and stabilizer added. Proper pool salt will range from $6-$14 per 40 pound bag, depending on your region. You can get away with using non-pool specific salt for short term savings. Since it isn’t as pure or fast dissolving, you’ll wind up spending more in the long run.
The cost will really vary on the pool and how long your chlorine generator components last. If you do the quick math from the figures above it is pretty close. If you aren’t doing anything other than adding salt then you may be saving money in the short term and think maintaining the pool is easy and inexpensive but the problem is the pool isn’t being maintained and that will certainly cost you in the long run. Clear water doesn’t necessarily mean the water is clean, free of bacteria and other contaminants or issues that will be caused due to the neglect.
If clear water is your only goal, there are plenty of cheaper alternatives. However, assuming you want a safe, properly balanced pool for your family and friends, it’s advised to keep up with all of your pool’s chemical needs and that will need to be factored into the total cost.
Physical Side Effects
Another misconception is the physical side effects that are attributed to a chlorine pool. Red eyes are usually a result of combined chlorine issues caused by water that isn’t shocked regularly. Since both systems are using chlorine this can be an issue for both systems although the salt in the water may have a more soothing effect over chlorine tablets in this scenario. Green hair isn’t even caused by chlorine contrary to popular belief. It is caused by copper in the water so either pool that has high levels of copper in the water can produce green hair.
As you can see, the over costs are close to even and are subject to change largely based on pool needs and personal preference. Before making a purchase you need to ask yourself: What can I afford in a worst case scenario? How much effort do I want to put into maintaining my pool? What do I want to get out of my pool?
Our recommendation at Sunplay is to do your homework and decide what you think will work best for you. If you are a current pool owner and already using a sanitizing system and it is working for you, we wouldn’t recommend switching. If what you are doing isn’t working out for you then switching to something else may be the way to go. There are a lot of chemicals systems on the market and other sanitizing systems such as UV Systems and Ozonators that are excellent choices that deserve a look. There isn’t a perfect system on the market or one that will save you a ton of money over another. Chlorine Tablets and Chlorine Generators can both be great options but one won’t necessarily be cheaper than the other.
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