Ionic silver and copper can eliminate algae and bacteria while reducing chlorine demand

Silver is used as a powerful bactericide in many products, and copper is used as a common algaecide. As water contacts these minerals, positively charged ions are released; these destroy negatively charged contaminants. And that makes these particular minerals well-suited for use as supplemental sanitizers in residential swimming pools and portable spas.

Ions at work

Silver and copper are most effective in water in their ionic form. That means the molecules are independent from other compounds and carry a positive charge. These charged ions are attracted to negatively charged organics such as bacteria and algae. Once attached, these ionic elements destroy the organics by penetrating their cell walls.

Because the ions are unaffected by sunlight or heat, they can remain active in water for long periods. They are only removed by reacting with the organics or from splash-out. There must be a constant flow of these charged ions introduced to the water in order for this process to be effective.

Active and passive ionization
There are two types of devices manufactured today that accomplish this process — one using an active method and the other using a passive method.

Active-method devices create ionic silver and copper by applying a low-level direct current to electrodes that are plumbed into the filtration system. The electrodes, which are made from combinations of silver, copper and sometimes zinc, quickly release their ions into the water as they erode from electrolysis. The electrodes must be replaced periodically, and the water must be tested regularly to ensure the silver and copper levels do not rise to a point where staining could occur.

Sequestering agents are recommended with this method to prevent any possibility of staining. These devices were common in the 1980s and ‘90s, but they never reached mainstream status as sanitizers. Most pool professionals feel they were oversold as a total replacement to chlorine, or were installed and used improperly. Recent technology seems to take into account the lessons learned from the past, but ionizers are not what most people think of when mineral sanitizers are discussed.

Passive-method devices are usually what come to mind when discussing mineral sanitizers. They do not use any electricity, instead utilizing a flow-through cartridge containing a substrate that is coated with silver or impregnated with a combination of silver and copper. The substrate is made of small pebble-sized pieces that are retained in the plastic cartridge. The cartridge is then installed in a vessel that is plumbed into the pool’s filtration system. As the water passes over the substrate, silver ions or a combination of silver and copper ions are slowly released.

Sequestering agents are not necessary, since the ions are released so slowly. The cartridge contents will remain active for up to 6 months in pools and 4 months in portable spas. Passive devices are also a perfect complement to salt-water chlorinators. They do not interfere with chlorine generation, and many users find that they can turn the chlorine production rate down, making the electrolytic cell last longer. Passive devices are a preferred method of using copper and silver vs. adding them via a powder or liquid form, because those products usually are mixed with chemicals.

Safe sanitizers
The U.S. Environmental Protection Agency (EPA) plays an important role in the regulation of mineral sanitizers. While the copper and silver elements are considered safe, when an efficacy claim is made regarding algae or bacteria control, the EPA regulates its use. Therefore, make sure the product you use has an EPA registration number, lists the active ingredients, and shows all the cautions that the EPA requires. Though the EPA regulates and verifies the claims of mineral sanitizers, they do not regulate the product’s potential to stain or cause other problems. Look for products that are guaranteed to work and guaranteed not to stain the pool.

Benefits of mineral sanitizers

Neither the active nor passive methods eliminate the need for chlorine in a swimming pool, because minerals lack the ability to oxidize dead contaminants. Fortunately, the two biggest benefits of using minerals are a reduction in the amount of chlorine needed to maintain a residual, and the ability to maintain a lower residual. With a mineral sanitizer, you will notice at least some of the following:
• No more algae
• Fewer complaints about skin and eye irritations
• Fewer shock treatments required
• Fewer pH adjustments needed
• The TDS reading does not increase as quickly

The best testimonials for mineral sanitizers come from the pool professionals who use them. They report many benefits, such as getting rid of problem algae spots, lowering chlorine use, more consistent chlorine readings, and pools that stay sparkling clear with less work.
Source: Dan Kellog- Pool and Spa News | 8.13.2010

Make sure saltwater pools are properly prepared for the beginning of swim season.

The initial steps in opening a saltwater pool are very similar to traditional pools, but a few key stages are critical to ensure the right start for the summer.

Get ready

First, for both types of pools, remove any plant debris that accumulated on the cover over the winter. Any plant matter that has made its way into the pool must also be removed. If water has collected on the cover, pump it off and away from the pool before removing.

Once the pool is clean, adjust the water level to about halfway up the skimmer face. You may need to add or remove water to reach this level, depending on your off-season climate and whether winterization was necessary. Connect the equipment, checking the pump and filter to make sure they are working properly, and turn it all on.

For saltwater pools, if you removed the electrolytic chlorine generator (ECG) during the off-season — particularly common in colder climates — put it back in place without turning it on. Pool water must have proper salt levels for the ECG to run correctly, so it shouldn’t be activated until after salt levels are checked and adjusted if needed.

Then run the pump for at least 24 hours to thoroughly circulate the water. This will help clear hazy water and filter out any remaining debris that found its way into the pool during the off-season.

Special salt steps

After preliminary opening tasks, startup steps for saltwater pools become more distinct.

For instance, saltwater pools must be shocked with chlorine. During the swim season, the ECG produces a constant amount of chlorine, so shocking a pool isn’t typically necessary. However, this fixed chlorine amount may not overcome the chlorine demand at startup that often is created by organic matter in the pool. A chlorine shock will solve this problem.

Before determining the pool’s salt level, take a water sample from a spot in the pool that is elbow-deep, away from the return lines, and test for and adjust pH, total alkalinity, calcium hardness and cyanuric acid. After the water is balanced, test for salt levels to ensure that the water has the appropriate amount for proper ECG function. The typical ideal salt level falls between 3,000- and 4,000 ppm, but instructions from the ECG manufacturer should be followed for optimum performance.

Run the ECG on its highest level of chlorine output for at least 24 hours to establish the proper amount of free chlorine. Once you’ve reached a level of free chlorine between 1- and 4 ppm, decrease the output according to manufacturer instructions to maintain the proper chlorine level throughout the season.

Benefits of salt water
Research shows that most traditional pool owners who have swam in a saltwater pool believe they deliver superior sensory benefits, and would prefer to own one over their existing vessel. The water created by a saltwater system is only about 1/10 the salinity of ocean water, so it feels softer and more soothing to the eyes, nose and skin.

Saltwater pools also can mean less maintenance. The ECG constantly converts salt water to chlorine, so chlorine levels are more consistent and there’s no need to purchase, transport, store, handle or frequently add chlorine.

Making the switch
If your customer has decided to switch to a saltwater pool, there are special steps needed for a smooth conversion. First, select the right-sized ECG according to pool size and bather load. If your customer has an
average-sized pool that is used heavily during the season, you may need to purchase an ECG that’s sized for a larger pool. This will ensure sufficient chlorine production for the pool’s actual usage.

Add treatment products to protect the pool against staining and scale as usual, but again, make sure these products are specifically designed for saltwater pools. The interior of the ECG has extreme pH ranges, high chlorine levels and relatively high temperatures. Many treatment products designed for traditionally sanitized pools break down into compounds like orthophosphates, which are nutrients for algae. The products used for salt systems should not contain ingredients like sulfates, or phosphorous-based sequestrants that can contribute to scale formation on cell plates.

Always use high-quality salt, especially when adding it to a customer’s pool for the first time. Commodity salt contains naturally occurring contaminants that can hurt your pool. Organic contaminants can cause scale, cloudy water and chlorine demand in the pool. Inorganic contaminants such as manganese, copper, iron, nitrates, silicates, sulfates, calcium and metals can affect water clarity, dissolution rate, and stain and scale potential. Check with your salt supplier to be sure of the type and source of the salt you are purchasing. Ultra-pure, mechanically evaporated salt is best for saltwater pools. Solar salt often has organic contaminants, and mined rock salt should never be used in pools.

When adding salt, use enough to reach the midpoint of the range recommended by the ECG manufacturer. It’s better to add too little salt than too much, as you can always add more; too much salt will require dilution with fresh water. Add salt to the deep end of the pool and brush until dissolved while the pump is running.
Saltwater pools require less maintenance than traditional pools, but they aren’t maintenance free. For residential pools, I recommend weekly testing for pH and chlorine, and monthly for total alkalinity, calcium hardness, stabilizer/cyanuric acid, metals and salinity levels to ensure they are maintained at the proper levels.

Source: Bob Harper- Pool and Spa News | 5.14.2010

With an understanding of galvanic corrosion, stains in salt-chlorine pools don’t have to be a mystery.

Source: Terry Arko- Pool and Spa News | 8.14.2009