Pool and spa ionizer questions and answers

Common questions about pool & hot tub ionizers

What is the difference between mineral pools and salt water pools?

The biggest difference between salt water pools and mineral pools is the amount of chlorine required to maintain the water. Mineral pools require chlorine in the range of 0.5ppm to 1ppm (or a minimum of 0.6ppm in Canada). With salt water pools, the recommended chlorine level is 1ppm to 3ppm.

The next major difference is the maintenance required. The salt chlorination process converts salt in the water to liquid chlorine. Liquid chlorine has a high pH, so if you don’t monitor and correct it frequently, it will quickly increase the pH of your pool beyond the typical 7.2 to 7.6 range that you want. Minerals have no effect on pH, so you will not need to use pH Down or pH Up chemicals as often to balance the pH. Salt water chlorinators also require maintenance on the salt cell. If the salt cell is not cleaned properly once a year, it will scale up and stop producing chlorine. If you are in an area with really hard water, you will need to clean the cell more frequently for it to continue producing enough chlorine.

Finally, mineral pools are more economical than salt water pools. The up front investment is less, the ongoing maintenance and chemical costs are lower, and the power consumption is lower.

Can ClearBlue be used on salt water pools and is there any benefit?

Yes, you can use ClearBlue on your salt water pool. Minerals allow you to reduce the chlorine requirement, so you can turn down the salt chlorinator to the lowest setting. This helps prolongs the life of your salt cell.

Since your salt chlorinator is generating less chlorine, there will be less fluctuation in pH. This will help save the chemical cost and time associated with balancing pH.

If you live in a climate with a lot of hot sunny days, minerals also help the salt chlorinator keep up with algae growth.

How does ClearBlue compare to other ionizers on the market?

The ClearBlue proportional control regulates the ion level in the water to keep it stable as conditions such as temperature, salinity and conductivity change. This is done automatically by the controller without adjusting the settings. Without this feature there may be excessive electrode wear and over-ionization, or not enough minerals causing extensive algae growth.

Whereas many ionizers use copper only, ClearBlue uses a proprietary blend of pure silver, copper and zinc. This blend has been laboratory tested under all conditions to ensure optimal control of bacteria and algae without overloading the water with minerals.

Copper is very effective at controlling algae, but you need the silver to control bacteria and viruses. Zinc reacts with the minerals to keep them in solution and prevent them from plating to metal surfaces like ladders or staining your pool walls. In spas and hot tubs, the zinc in the water is also good for your skin.

ClearBlue is very simple to operate compared to some models which combine both copper ionization and oxidization. Once you get the settings right for your pool, you never have to touch them again except when you need to ramp up the minerals after a refill. While you should also monitor the mineral levels with your pH, chlorine and other tests, there are no toggles or manual modes to change.

Price wise, ClearBlue is right in the middle – not too cheap and not expensive compared to less popular ionizers. Our aim is to provide the right value vs. a salt water pool or traditional chlorine pool.

ClearBlue is the only ionizer registered with CSA, UL, EPA and Health Canada and has been on the market since 2004.

How long do the mineral cells last?

The rule of thumb is that the ClearBlue mineral cells will last six to twelve months in a pool or one to three years in a hot tub or spa.

The biggest factor is how big your pool is. A larger pool will require more minerals, so the electrodes will wear down quicker.

Another factor is how much sun you get. The more sun you get, the more algae wants to grow, so the more minerals will be needed.

The first cell will go quicker because the minerals need to ramp up in the water. This is especially true in larger pools. Once the minerals have built up, they are very stable, even over the winter. So subsequent cells will last longer.

Are mineral pools 100% chlorine free?


According to the EPA and Health Canada, no pool system is 100% free of chlorine (or bromine). The lowest chlorine residual recommended for any pool system is 0.5ppm (or 0.6ppm in Canada).

The pool and spa industry is flush with conflicting opinions, misleading information and downright lies. If a pool store or pool equipment vendor tells you that their system is 100% chlorine free, we suggest you keep looking.

While chlorine can increase the risk of asthma and potentially other health conditions, it is also very effective at breaking down organic material and controlling the bacteria and viruses that can make you sick. According to this study on WebMD, the chlorine level in mineral pools is low enough to reduce the risk of getting asthma down to the same level as swimming in lakes and rivers.

Some people have an extreme sensitivity to chlorine and must avoid it completely. However most of us can tolerate it at very low levels where the benefits far outweigh the risks. This is why most municipal drinking water is sanitized with it.

How much chlorine or bromine residual sanitizer do I need?

The EPA recommends a minimum chlorine or bromine of 0.5ppm in mineral pools and spas. Health Canada recommends a minimum of 0.6ppm in pools and a minimum of 3ppm in spas and hot tubs.

To maintain this level in pools, we recommend adding one 3″ stabilized chlorine tablet every week in a pool from 20,000 gallons to 40,000 gallons and every two weeks in a pool from 5,000 gallons to 20,000 gallons.

How do I open my ClearBlue mineral pool?

You can open your ClearBlue pool the same way as any chlorine or bromine pool. We recommend shocking the pool and adding algecide if needed before starting the pump and filter.

Once everything has been running for a few days, you should test the mineral ion levels and adjust the ClearBlue controller settings as required. It’s also a good idea to have your water tested at a store for other imbalances.

What is the power usage of the ClearBlue controller?

The 120V controller draws a maximum of 0.1A. The 240V controller draws a maximum of 0.05A.

Does the ClearBlue Ionizer filter the water?

No, ClearBlue is not a filter. You must use a standard pool or spa filter and follow the directions from the manufacturer for filter maintenance.

Are mineral ions harmful if my pets or kids drink the pool water?


The maximum amount of copper that is allowed in drinking water is 1.3ppm. Our controller will maintain a maximum of 0.4ppm if properly configured.

The other minerals used are present in trace amounts and within the allowable levels for drinking water.

Will the copper turn my hair green?


There have been cases of people getting a green tint in their hair after swimming. This is caused by a combination of high chlorine levels (above 5ppm) and high copper levels (above 1ppm). The chlorine at high concentrations opens the door for copper to stain the hair.

When used as directed, your ClearBlue system will output a maximum of 0.4ppm of copper. The chlorine in your mineral pool should be maintained at a maximum of 3ppm. Our recommendation for chlorine, which is endorsed by the EPA is to maintain 0.5ppm – 1ppm chlorine. Health Canada suggests 0.6ppm – 3ppm.

At these levels, you would have the same chance of getting green hair as you would in your shower.

How long does it take to get the mineral ions up to the recommended levels?

The operating manual provides guidance on the settings for your pool or hot tub to minimize the mineral ion ramp up time.

The larger the pool, the longer it will take to ramp up the minerals.

The rule of thumb is 7-14 days for a pool and up to 7 days for a hot tub.

Once you get the ions up to the correct level, they are very stable, so you should not need to adjust the controller settings once you reach the recommended level of 0.2ppm to 0.4ppm.

Does it matter if I have a heater or if the water gets very warm?


The ClearBlue controller maintains a constant output of mineral ions and compensates for the temperature and conductivity of the water.

Can I add a stain & scale (sequestering) agent to the water?

Stain & scale preventing sequestering agents are needed if you have source water with high concentrations of iron, calcium, lime etc. Although these products are designed to remove iron and calcium, they will also remove the ClearBlue mineral ions.

Unlike salt chlorinators, ClearBlue mineral pools are not affected by calcium hardness, so even with high calcium levels, a stain & scale product is not required.

If you have a serious staining concern due to high iron in your water, you can treat the water at the source using a metal trap filter. This filter can be attached to your garden hose and will remove contaminants before they enter the pool or spa.

We figure it’s better to remove contaminants at the source, rather than add them to the pool and then remove them with chemicals.

If you have already put a sequestering agent into your pool, it will not damage your ClearBlue system, but we recommended unplugging the ClearBlue controller for 4-6 weeks because the sequestering agent will neutralize new minerals, so you will be wasting the cell.

Also, it is okay to use a stain & scale or sequestering agent when you are closing the pool

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