By Alicia Stephens
The primary concern for any pool owner is the unpleasant sight of a green pool. Nobody wishes to gaze into their backyard and see murky, green water or a pool overrun by algae when it should be crystal clear. There are many different types of algae in the world, and several of them can flourish in the pool environment. As such, a critical aspect of pool water maintenance is averting algae growth, making it essential for both pool owners and service professionals to include a weekly preventive algaecide as part of their routine. Taking a more in-depth view, one can explore strategies to prevent the proliferation of algae and identify the necessary steps to address an algae outbreak.
Understanding algae in pools
The first question that always comes up concerns the origin of algae. In certain scenarios, a pool can undergo a rapid transition from crystal clear to swampy green overnight, making it challenging to determine its source. Algae is consistently introduced to the pool from a variety of sources. Algae spores from various species can be traced back to natural water bodies, plants, soil, and trees. Further, rain, wind, swimmers, and animals—specifically birds—are among the various contributors responsible for introducing algae to pools. In fact, a single bird can introduce more than 100 different types of algae to the pool environment. The short answer is algae find their way into pools from virtually everywhere.
In the absence of adequate algae prevention measures, once algae spores are introduced into the pool, they will immediately start to grow and reproduce. Left unchecked, a single algae cell can ultimately multiply into more than one million algae cells, leading to a significant algae bloom in the pool. A fundamental strategy for maintaining clean and clear pools is to proactively hinder the growth and reproduction of algae from occurring. Addressing an outbreak is substantially more challenging than preventing one in the first place.
In the pool industry, algae are typically categorized into three main types: green, yellow (or mustard), and black algae, each characterized by distinct attributes. Green algae is often the easiest to get but also the simplest to eliminate. While pools can turn green quickly, they can be cleaned up swiftly in most instances. In many cases, employing an Environmental Protection Agency (EPA)-registered chlorine-based shock treatment, along with effective circulation and filtration, can take care of the issue. Yellow algae, also known as mustard algae, has a yellowish appearance and is commonly found on the bottom of the pool. When disturbed (e.g. by brushing), it tends to disperse (fluff up) but typically settles back in the same area, making vacuuming it up a difficult task. Black algae, although it is not algae but cyanobacteria, manifests as a distinct growth on the pool surface. It adheres firmly, rooting itself into the plaster and becomes quite difficult to brush up and remove. The most effective approach to eliminate black algae usually involves vigorous brushing and direct application of chlorine or algaecide. It is essential to perform a spot test in the targeted area before employing direct application treatments.
