Swimming Pools, Part 2—Should You Go With Chlorine, Saltwater or Ultraviolet Light Sanitation? — BYHYU 085
Last week we talked about the pros of cons of the different types of pool construction. After you decide what type of pool structure you want, you’ll have to decide want type of sanitization system you’ll use to keep your pool free of bacteria, viruses and algae.
The most common systems are chlorine, saltwater, and ultraviolet light. Let’s briefly go over each system and discuss the advantages of each.
Chlorine pools are still the most common type of pool built today. Chlorine kills mold, mildew, bacteria and other microorganisms living in water, making water safer to swim in. Chlorine tablets are used to sanitize a chlorine pool and those chlorine tablets are readily available, even in some stores that don’t specialize in pool supplies.
Chlorine pool water needs to be tested regularly with a kit. Chlorine tablets are added as needed to balance the pH levels of the water. The tablets are added to either a pump unit, separate from the pool water, or to a floating disbursement device that dissolves the chlorine tablets over time in the water.
Chlorine pools require more maintenance and more seasonal chemicals when compared with saltwater and UV systems. Water levels, and as result, pH levels, will vary from week to week due rain water, backwashing or water loss due to splashing and evaporation. Chlorine must be added regularly to balance those ph levels.
ADVANTAGES OF A CHLORINE POOL
1. A chlorine system will clear water up much quicker than other systems. If there is overgrowth of bacteria, or if the pH levels are off, a chlorine system can clean and balance water in about 24 to 48 hours. It may take 3 to 5 days for a saltwater system to clear things up.
2. The initial set up cost for a chlorine pool is significantly lower than the set up cost for a saltwater pool. Initial set up for a saltwater pool is between $1,000 and $5,000, and that doesn’t include the cost of the construction of the actual pool. The major part of that expense comes from the purchase and installation of a saltwater chlorine generator, which you obviously won’t need with a chlorine pool.
3. A chlorine pool typically uses a little less electricity than the amount of electricity needed for a saltwater pool system.
Lots of people think that a saltwater pool is better than a chlorine pool. But, in a way of speaking, a salt water pool IS a chlorine pool. The chemical name for salt is sodium chloride. Remember that from chemistry class? In a saltwater pool, sodium chloride is electrically converted into chlorine.
Although a significant amount of salt is dissolved in the pool water to clean and sanitize the saltwater pool, the water won’t taste really salty like ocean water does. In fact, saltwater pools have 1/10 the salt of the ocean.
In a saltwater pool, you have to maintain consistent salt-to-water ratios and pH levels by adding salt or water to the pool on a weekly to monthly basis. Factors like how much rain water has gotten into the pool and the amount of water that’s been lost due to splashing or evaporation will affect the salt-to-water ratio.
The initial up-front cost of the saltwater pool is much greater than the up-front cost for chlorine, as we just discussed. But over time, the cost goes down significantly because it’s mainly the water in the pool that’s lost or gained, not salt. The amount of salt in the pool remains relatively stable, so only small amounts have to be added to maintain salt-to-water ratio.
ADVANTAGES OF A SALTWATER POOL
1. Saltwater pools are low in maintenance and low in overall maintenance cost.
Within the first few years of owning your saltwater pool, you’ll get back that extra cost you paid for the installation of the saltwater system. You’ll get that cost back in lower maintenance and chemical costs. The most up-to-date salt water systems can maintain a clean, clear pool for up to two weeks without intervention. In contrast, a traditional chlorine pool requires weekly maintenance with chlorine tablets added regularly.
A chlorine pool will also need periodic “shocks” of more concentrated chlorine to keep algae from growing and to maintain consistent chlorine levels. This involves dissolving chlorine in a bucket of water and adding it slowly to the pool. A saltwater pool needs this shock treatment usually only after an heavy rain or when algae begins to grow, which starts to turn the water green.
2. Saltwater is less irritating than water from a chlorine pool. This is probably the biggest reason to choose a saltwater system over chlorine. Although saltwater systems produce chlorine for sanitization, the levels are low enough that the chlorine in a saltwater pool usually won’t hurt or sting your eyes, irritate your skin, damage your hair, fade your swimsuit or cause headaches. Plus, the chlorine produced from salt is less harsh than chlorine chemical tablets.
A saltwater system is meant to provide the same benefits of a chlorine pool, but without all the irritating chemicals.
ULTRAVIOLET LIGHT SYSTEM
Ultraviolet (UV) pool sanitizers use a non-chemical system of invisible UV light rays to sanitize water. Ultraviolet pool sanitizers emit a high intensity light ray that destroys algae, bacteria and viruses, as well as some chlorine-resistant parasites. UV systems also eliminate the formation of chlorine by-products.
About 80% of new water parks and aquatic facilities use ultraviolet sanitation systems.
But here's the catch...
According to waterandhealth.org, alternative pool sanitizers, including UV systems, “still require a secondary level of protection, most often provided by chlorine-based sanitizers”.
Although UV light systems effectively kill many germs, the system must be used along with chlorine for residential pool sanitation. That’s because UV systems work by moving the pool water past the UV lamps, where germs are destroyed. In residential pools, unlike many waterparks, water doesn’t circulate quickly enough around to the UV light. That means it may take too long for germs in the distant part of the pool to get exposed to the ultraviolet system.
During that lag time, bacteria, algae, viruses and parasites can grow and multiply. So adding germ-killing chlorine to a UV system is ideal for a residential pool. But you should still consider installing a UV sanitizer since it should help you decrease the amount of chlorine needed for your pool.
UV systems are expensive, ranging from $500 to $2000. But they are still relatively new on the market, so hopefully prices will fall over time. The UV system itself is super low maintenance, typically needing only a yearly UV lamp replacement and a cleaning of the quartz tube that’s inside the UV unit. But remember you’ll also need to add chlorine regularly for optimal sanitation.
Let’s end with a quick tip about getting the best price for your swimming pool installation. Get several bids and have your pool installed in late summer, early fall or very early spring, when the pool business is typically slow. You might even see if you can get some winter specials if you live in an area where the ground doesn’t typically freeze.
Cost, maintenance and health concerns are the main reasons to choose one sanitization system over another. When making your decision, be realistic about your budget and your sensitivity to chlorine and your willingness to perform, or pay for maintenance.
Well, that’s for this week. I hope you learned as much as I did. Let’s do it again next week. Come on back for the next episode of BYHYU.
Please remember that the purpose of this podcast is simply to educate and inform. It is not a substitute for professional advice. The information that you hear is based the only on the opinions, research and experiences of my guests and myself. That information might be incomplete, it’s subject to change and it may not apply to your project. In addition, building codes and requirements vary from region to region, so always consult a professional about specific recommendations for your home.