Are Pool Algaecides Needed?

Why Do I Need To Use Algaecide In My Swimming Pool?

Algaecides and algaestats treat and prevent algae growth in pools and hot tubs and are important tools to keep in your pool care arsenal. While the chlorine you use for regular pool maintenance and water sanitization does have bactericidal and algaecidal properties, the addition of pool algaecide will enhance and prolong the effectiveness of the chlorine and can act as a valuable backup to the anti-algae effects of regular chlorination. If algae are present in your pool despite your regular pool care routine, which can be indicated by brown, green, blue-green, black or yellow areas on the walls of the pool or an algae bloom in the water, then using algaecide is definitely in order. The most common forms of algae are extremely resistant to treatment with chlorine. Therefore, algaecides will be necessary to rectify the situation and return your pool to the clean, clear, refreshing haven as intended.

The chemistry of algaecide is pretty complex since there are more than 46 species of clear water algae that exist today. Some types of algaecide work better on certain species of algae that others. Algaecides are primarily algae inhibitors that work in conjunction with pool sanitizers to help control and prevent algae growth. Planktonic clean water algae float on the surface of pool water while other types will attach and grow onto the pool floor or sides. Many factors affect the development and growth rate of algae. Water temperature, sunlight, pH, mineral content, poor water circulation and low sanitizer residual will all help to encouage algae development if the water is not balanced or the potential for problem addressed. So how does algae get into your pool? Algae spore can be introduced to the pool by rain, falling leaves, wind or even bathing suits transfering algae from one body of water to another. 

Because wind and rain is constantly introducing algae spores into your pool water, prevention is the key component to managing algae concerns before they become a problem. Inadequate pool water circulation and pool sanitizer and shock treatment is the main contributory cause to pool algae development. Algaecides and algaestats are a good idea if the conditions where you live favor algae growth, such as areas that routinely experience high temperatures, large amounts of direct sunlight or heavy rain. If you find that for what ever reason, you just do not seem to have the time to take care of your pool water as you should and as we advise, then algaecides should be added to your pool care. Once algae is visible in your pool, the algae colony is already well established, which can quickly cause your pool to become dangerously slippery and can begin to increase the pH level significantly. As the pH rises the sanitizer becomes less effective. You can avoid this by incorporating algaecides and algae stats into your pool care routine.

What is the difference between pool algaecides and algaestats?

Algaecides are used to kill algae; whereas, algae stats are a proactive treatment that is used to prevent the growth of algae. In many cases, the difference between algaecides and algae stats is simply the dosage strength of the chemical formula used for treatment. For example, algae stats that are recommended to be used once per week to inhibit algae growth will likely be similar to the chemical formula of an algaecide that is a concentrated strength to kill existing algae. There are several different types and strengths of algaecide, from 5%, 10%, 30%, 50% to 60%. Typically the lower precentage of concentration and effectiveness are sold by mass merchants at seamingly lower prices. Choosing the right one for your pool may seem to present a challenge so, we'll try to help as we read on. Although the is no test for algaecide levels in the water, following the manufacturer directions for use on the label to maintain a working algaecide level in the pool is an effective deterrent to algae development.

Which Pool Algaecide Should I Use?

Which algaecide will work best for your particular situation depends on the type of algae growth you are experiencing in your pool. For example, most algaecides are effective against green algae, but black algae may require an algaecide specifically formulated to treat this resistant type. Below are brief descriptions of the four primary types of algaecides commonly used to treat swimming pool algae. There are also strong algaecides blended with water clarifiers to help your filtration system remove dead algae from the water. The most common type of algaecide is called quaternary ammonium formulas or "Quats". However, quats cause foam to form on the pool water surface due to their ability to also decrease water surface tension. Foaming is perfectly normal for quats and the foam will have a short presence in your pool. These are available in the 5%, 10% and 30% concentrations, Their formula is very effective as algae inhibitors. The precentage gives you indication of effectiveness. Another type of algaecide that does not produce much foam has a polymer additive to prevent it. These Low-foaming algaecides are called "poly-quats" and are available in 50% and 60% strengths. This is the algaecide that we recommend most for any pool type and it is best suited for your weekly pool care routine. As little a 2-4 onces will treat 10,000 gallons per week. There are still other types that are designed to be more specific that have silver, copper or magnesium added to them to destroy those hard to kill algae such as pink slime, mustard or black algae. 

What the differences are between Algaecides for Swimming Pools:

Copper Algaecides
Copper algaecide kills algae through suffocation and metabolism disruption and are an effective treatment option for most types of algae. They are highly effective when used to treat green algae or mustard algae and do not have the foaming issues associated with quaternary ammonia algaecides; however, if not used at proper levels, elemental copper-based algaecides can cause staining on some concrete pools. Most copper algaecides include a chelating agent to help prevent this. Copper algaecide is a good choice for use in vinyl liner pools. You should not use a copper algaecide with a biguanide based sanitizing system such as Baquacil®, Splashes®  or SoftSwim®. There are two common types of copper algaecide. The first contains Elemental Copper which is approximately a 7% active ingredient concentration. Don't let it's low precentage fool you, one quart can treat up to 160,000 gallons of pool water. It should be added to the pool water weekly. The other type is approximately 11% Copper Sulfate Pentahydrate. This type of copper algaecide is non-staining. The manufacturer recommends that you add about 16 ounces per 10,000 gallons for 3 months of protection, so it very convienent in a pool care routine. It treats blue-green, green, yellow and black algae. 

Quaternary Ammonia Algaecides
Quaternary Ammonia algaecide, also called Quats, are the most cost-effective product to use as both an algaecide and an algaestat. Effective in both capacities, quats work best against green algae and kill algae growth through cellular membrane disruption. While quats do not case staining, foaming can occur, especially when not used properly. If you have experienced any metal staining in the past, you should use a quat or polyquat algaecide to treat your swimming pool.

Polyquat Algaecide
Polyquat algaecides are a highly effective treatment option for all types of algae and do not have the staining issues of copper algaecides or the foaming issues of quats. Polyquats are stronger algaecide formulas that kill algae through cellular membrane disruption, similar to quats, but are composed of longer molecular structures. This type of algaecide is safe for use in any pool yet tends to be more expensive and more effective than other options. If your pool is already algae infested, shocking the pool with a large amount of chlorine shock is still the first choice and then when the chlorine level has returned into the normal range, the algaecide treatment will be more effective.

Black Algaecide
Black algae killers and algacides are specially formulated to destroy black algae (dark blue-green algae), which can be very resistant to chlorine and other algaecides and algaestats. These algaecides are generally a proprietary blend of a copper-based algaecide and a quaternary ammonia algaecide and are highly effective in both preventing and destroying black algae. They work through a combination of cellular membrane disruption, metabolism disruption and suffocation. Black algae forms in layers within the small crevices of concrete and plaster finished pools. Once established, black algae are tough to get rid of because chlorine alone has little effect, and on only the surface layer of the algae. Using a stiff brush, you must first break through the algae surface layers for any algaecide or chlorine treatments to be effective and then you need to maintain higher chlorine reading (3.0) and lower the pH to 7.2 for a period after treatment to destroy this form of algae.

As you can see, each formula of pool algaecide has a specific purpose and treats certain types of algae. Always buy a concentrated algaecides to treat or prevent the algae your pool is prone to experience. Do not buy gallons or half gallons of cheap algaecides typically available at mass merchants. Most of there products are very weak quaternary ammonia formulas and not a good value.