The Good, the Bad, the Ugly
Copper has been used for water treatment for thousands of years. Ancient Greeks, Romans, and Vikings all discovered how copper could prevent algae. Using copper in a pool is a relatively recent development, with both benefits and drawbacks.
The pool industry has developed this discovery into various products used to treat algae. But can I drop a piece of copper into the pool skimmer and get the same results? Kind of. However, some risks should be taken into account.
What causes high copper levels in pool water?
Copper can enter your swimming pool in several ways. Since most residential plumbing is made of copper, you might even have copper from a fresh fill in the pool. Small amounts of copper from the pipes dissolve in the water and can enter the pool when it is filled.
If you fill your pool with water from a well, the water may contain copper, but well water is more likely to contain iron. Both copper and iron can be removed from the water by filling the pool with a hose filter.
Copper algaecides can also raise the copper level. Several products on the market use copper as the active ingredient to kill or prevent algae.
Pool ionizers that use copper can cause high copper levels in your pool. Many pool ionizer systems are overpowered, making it easy to achieve high copper levels. However, even with properly regulated pool ionizers, it is essential to be aware of the settings and frequently test the copper level to ensure it remains within the correct range.
Does copper kill or prevent algae in pools?
Yes! Copper is one of the most well-known minerals for controlling algae growth. So, a small dose of copper will eliminate algae and keep it away. As mentioned above, several copper algaecides are available on the market. Some are high concentrations, intended to clear up green water; others are lower concentrations, designed to prevent algae growth; and some are mixed with chlorine or other sanitizers.
Copper pool ionizers are designed to treat algae in pools. Some are powerful enough to kill back an algae bloom, but that added power means there is a higher risk of staining from high copper levels. Other systems are designed to maintain a low copper residual that is sufficient to prevent algae but not enough to clear up the water if it has become green.
Can I put copper pennies or copper fittings in my skimmer?
Adding copper fittings, pipe, or pennies to your pool can affect algae growth. The copper from the metal objects slowly dissolves and reacts with the water, creating copper ions that are toxic to algae. However, this probably isn’t the most effective way to control algae in your pool. The dissolving process is very slow, and it will take a long time to generate enough copper ions to be effective.
Some products on the market use copper pipes for algae control. This only works well when used in conjunction with other products that accelerate the release of copper into the water. Simply dropping a copper pipe in the pool skimmer probably won’t have the desired results.
How do I lower the copper level in my pool?
The ideal range for copper to be effective as an algaecide without causing staining is 0.2 ppm to 0.4 ppm. Therefore, the first step in removing it is to test for it. If it falls within this range, it’s beneficial, so there is no need to remove it.
If the copper level is around 1 ppm, it’s still not a huge risk, but it’s a good time to shut off the pool ionizer or stop adding copper-based algaecides. You can also add a ‘chelating agent’ like Copper Control, which ‘wraps’ the copper ions so they stay dissolved. This will reduce the copper level and help prevent staining.
If the copper level exceeds 1 ppm, determine the cause first. If you don’t have a pool ionizer and haven’t been adding copper algaecides, your heater might have a problem. Many heaters use a copper or bronze core (mostly copper). If the heater element is breaking down, normally due to age, it will release large amounts of copper into the water. If you have a heater and no other copper sources are being added, you should bypass it and have it serviced.
Once you have figured out the copper source, you can use a ‘sequestering agent’ like The Magenta Stuff, which completely removes copper and other minerals from the water.
What’s the best way to put copper in a pool?
Copper is a natural mineral that inhibits the growth of algae. Maintaining it in the proper range is a low-cost way to keep the water crystal clear without using many chemicals. Liquid algaecides and pool ionizers are the most common methods of adding copper to a pool.
The benefit of copper algaecides is that you can quickly increase the level, which is helpful if you are trying to clear a green pool. However, it’s easy to overdose the pool with copper, which can lead to staining.
The benefit of pool ionizers is that you can regulate the copper output and test for it. This makes it easier to keep it in the proper range for preventing algae, but not so high that it will lead to stains.
Copper swimming pool systems
For further reading, check out these systems and products that use copper for swimming pools.
Copper Control – Reduces copper levels in pools and spas
ClearBlue Mineral System – EPA-registered sanitizer for pools
Mineral Lion Pool Ionizer – Advanced but low-cost pool ionizer
Pristine Blue – Copper sulfate pentahydrate liquid for pools
Copper Algaecide – Concentrated chelated copper for algae bloom treatment
Pool Rx – Copper algaecide baskets
Amazon links on this page are affiliate links