Chlorine Alternative Comparison for Pool Owners - Essential Guide

How do you know what the best pool system is?

Historically, chlorine has been the default method of pool sanitation. At this point in time, however, the options for chlorine alternative pool systems are numerous, and they offer serious reasons to upgrade your pool from traditional chlorine if you haven't already done so. 

This guide for pool owners will help educate you so that you can choose the best pool system for your needs and budget. 

If you are already using one of these chlorine alternatives, this guide will help you better understand its pros & cons, and see how you might be able to make things even better and more economical.

1) Pool System Comparison Chart

2) Traditional Chlorination

Chlorine pools would be great - really, the ideal way to keep a pool blue and clear - if it weren't for just how large an amount of chlorine that the pool actually requires to stay blue & clear. And also, how much chlorine costs over time. And, how much chlorine keeps going up in price. And how frequently the pool needs chlorine added to it. And then, there is what happens when it doesn't get done perfectly - fighting algae and having to highly shock the pool to cleaer it up. There is also the pool chlorine odor, and the irritation, the dry skin, the red eyes... Well, chlorine is good at what it does, but the cost & hassle are real. You could add to the expense of conventional chlorine chemical management by paying someone to try and manage the situation the best they can, but the water can still be harsh to swim in.

Pros: Common, 100% effective with proper upkeep, cheap to get started.

Cons: Harsh chemical effects, requires frequent upkeep and can be the most work, can be most expensive long-term.

3) Salt Chlorination

According to Pool & Spa News, pools with salt systems have become the standard (7 out of 10 new pools were salt pools, as of 2016). This is likely because you get the 100% effective sanitation provided by chlorine, essentially without the drawbacks! Put simply, a pool salt system is just a chlorine generator. It uses a low-level of natural salt in the pool water to generate a pure form of chlorine - everyday, automatically when the pump runs. Not only is it almost effortless, it is cost effective: since you are generating your own chlorine, it can save up to 50% or more over conventional chemical upkeep*. Even better, it gets rid of the harsh chemical effects of typical pools - no more red eyes, itchy skin, or bleached hair and swimsuits.

Pros: 100% effective pool sanitation, dramatically less upkeep, long-term savings can potentially be the best return on investment.

Cons: Upfront cost of the salt system, still requires some maintenance (usually seasonally), chlorine generator cells require eventual replacement (fraction of the system cost).

4) Ozone Generators

Pools with ozone systems have two benefits that other sanitation system can't effectively rival. First, as a pool ozone system injects ozone into the water, it acts as a micro-flocculent that greatly clarifies the water. Second, ozone generators are extremely effective oxidizers - meaning they help deal with all the non-organic contaminants that build up in pools (some small pool and hot tub users even report that it gets rid of all the grime that has built up at the water line over the years). This means that ozone generators are able to reduce the pool's sanitation demand (how much chlorine the water requires) by up to 60-90%. Ozone is a great pool upgrade, but it still requires manual chlorination, or ideally, use of a salt chlorinator (some ozone + salt chlorinator combinations are even available).

Pros: High-definition water clarity, powerful oxidation of contaminants, doesn't usually require adjustments after setup.

Cons: "Point-of-contact" sanitization only when pump runs (no residual sanitation protection), ozone generating components and hoses require eventual replacement, micro-bubbles come out of pool jets (de-gas equipment recommended for indoor pools).

5) UV Light Systems

Pools with UV systems get the benefit of a reliable, "clean", "hands-off" secondary sanitation system. UV pool systems are essentially a large chamber that the water flows through where germicidal UV-light "deactivates" micro-organisms so they can't replicate. This greatly reduces the sanitation demand of the pool water, and it does so without adding a single other chemical to the pool - just the UV light passing through the water. UV pool systems can be inexpensive, easy to install, and require little-to-no maintenance after initial install.

Pros: Extremely simple, very economical, adds "zero" extra to the water

Cons: "Point-of-contact" sanitization only when pump runs (no residual sanitation protection), UV bulbs require eventual replacement, provides no oxidation

6) Ionizers & Mineral Systems

Pools with ionizers or mineral cartridge systems release metal ions into the water. These metal ions (typically copper and/or silver) have a very similar effect as the manual addition of liquid algaecide. Ionizers electrically generate metal ions, where mineral cartridges slowly dissolve into the water. These systems can help inhibit the growth of algae, thus lowering chlorine demand, but do not provide any of the oxidation that a pool requires. Additionally these ions are not fast-acting in the presence of pool contaminants, so ionizers and mineral cartridges are an alternative way to to supplement pool care.

Pros: Upfront cost can be lower than other systems, novel approach that is used by some purified water companies.

Cons: Slow-acting, does not provide required oxidation, cartidges/metal bars must be refilled/replaced, must be carefully monitored as ions can cause staining of pool surfaces & fingernails.

7) Chlorine Free / AOP Systems

There can be variation within this category, but these chlorine alternative pool systems utilize the generation of hydroxyl radicals. Like ozone, hydroxls are extremely effective oxidizers (even more so)

AOP systems are typically UV-Ozone combination units, where ozone gets "upscaled" into hydroxls as it passes through the UV light chamber. Some AOP systems are actually hydroxyl generators, that can create these higher levels of hydroxls.

Even though hydroxyls are even more effective that ozone, they also dissipate faster! That means they are highly point-of-contact pool sanitation; AOP and hydroxl generators typically specify that you run your pool pump 24 hours a day unless you also still add chlorine. Some systems help create a chlorine-free pool system by combining a hydroxyl generator cell with an ion generator, in order to provide a form of residual protection.

Pros: Latest & greatest technology, highly-effective oxidation, extremely fast-acting sanitation during operation.

Cons: Typically highest cost (premium), requires longer pool run-times, can still require another pool sanitation source (chlorine, non-chlorine shock, salt chlorinator, etc...).