Top 5 Winter Pool Algaecides

In this article, Let’s delve into the critical choice of selecting the best winter algaecide for your pool. Many pool owners face the dilemma of maintaining clear, algae-free water during the colder months. To address these concerns, I’ll guide you through different algaecide options, their effectiveness against cold-weather algae, and the nuances that set them apart from standard algaecides.

Key Takeaways:

  1. Effectiveness of Winter Algaecides: Discover how winter algaecides, specifically formulated for cold water, are crucial in preventing algae growth during the off-season.
  2. Top Winter Algaecide Choices: Learn about the best and most effective winter algaecides available, based on user reviews and proven results.
  3. Differences Between Polyquat and Metallic Algaecides: Understand the distinct advantages and disadvantages of polyquat and metallic algaecides for winter use.
  4. Strategies for Maximum Effectiveness: Gain insights into the correct application techniques and preparatory steps for using winter algaecides effectively.
  5. Winter Algaecide Vs. Regular Algaecide: Comprehend the distinct differences between winter and regular algaecides, highlighting why the former is essential for maintaining pool health in colder temperatures.

The Best Winter Pool Algaecides

I have researched what I believe to be some of the best winter algaecides. There is no affiliate marketing arrangement with them, and you may not necessarily agree with my choice. Try them and make the final decision based on personal experience.

Best Polyquat Winter Pool Algaecides

Polyquat algaecides are non-metallic, biodegradable, and eco-friendly, formulated using ammonia-based compounds. They are safer than copper-based algaecides and are non-staining and non-foaming. The polymer has a positive charge and attaches to the negatively charged algae, spreading over the surface and smothering it. Three of the best polyquat algaecides are:

GLB Algimycin Winter Algaecide

An alternative to copper algaecides, this is also a polyquat, which uses quaternary ammonium compounds instead of a copper formula. Polyquat algaecides treat and prevent algae growth differently from copper-based products, don’t cause staining of pool surfaces, and are non-foaming. The downside is that they tend to be more expensive and have higher recommended dosages.

GLB Algimycin is compatible with chlorine-, bromine- and saltwater-based sanitizing systems and is formulated to provide protection against all algae types, using ½ a gallon per 20,000 gallons in a solid-covered pool and one gallon per 20,000 gallons in a mesh-covered pool.

Proteam Polyquat 60

Rated 4.9/5 by users, this non-metallic algaecide is one of the more concentrated polyquats and is effective for all seasons, including winter. Formulated using polyethylene dichloride, it is compatible with other pool chemicals. The recommended dosage for pools that are algae-free at the end of the swimming season is 1 quart per 20,000 gallons.

Available in 1-quart containers at $39, it’s one of the more expensive algaecides but cost-effective because of the low dosage required. Customer reviews are very positive, so it’s included in this list of best winter algaecides.

Best Metallic Algaecides

While there are alternatives like silver, copper is used almost exclusively in the formulation of metal-based algaecides. It is usually bonded with amino acids to form an organocopper compound, making it less likely to cause staining of the pool walls. The metal algaecides contain positively charged copper ions that attach themselves to algae and poison them from the inside. Two recommended copper-based algaecides are:

In The Swim Winter Algaecide

In The Swim is a copper-based algaecide sold in 1-quart bottles, which will be sufficient to treat 20,000 gallons. This brand is also available as a polymer-based algaecide very similar to Proteam Polyquat 60, but I’ve included their winter algaecide in this list because it’s formulated to last up to five months and is effective in preventing green, black, and mustard algae all winter.

Poolife Algaecide 90

The 90 in the name refers to the number of days it’s effective in your winterized pool on a dosage of 32 fl oz 10,000 gallons of pool water. This dosage helps to prevent or at least limit algae growth during winter and helps to maintain the pool’s condition before the following summer.

How To Use A Winter Algaecide For Best Results

Winter algaecide is different from regular algaecides because it is specifically formulated to prevent the growth of cold-weather algae and remain effective for up to five months, even without the water circulating through the pool’s filtration system. To ensure that is the case, this is what needs to be done:

  • The pool must be free of algae during the swimming season and particularly at the time it’s going to be closed.
  • Brush down the walls and floor of the pool and remove all debris by vacuuming at least once. Clean out the filter thoroughly.
  • The chemical balance of the pool must be correct, and if you’re going to add shock before closing (which is a good idea), wait until the chlorine levels are back down before adding the algaecide. Never add the two products at the same time.
  • Add the algaecide directly to the pool, pouring it in slowly around the edge and allowing it to circulate for about two hours before turning off the pump and covering the pool.
  • Uncovered pools or those with mesh rather than solid covers may need a second dose before the end of winter.

Winter Algaecide Vs. Regular Algaecide

A regular algaecide is a product that kills algae and is usually used in summer when algae growth is more vigorous. Winter algaecide is a less concentrated form used to prevent potential algae growth during colder months when temperatures may fluctuate but are generally below 60⁰F.

Winter algaecides are formulated for cold-weather algae growth that may occur in pools that have been winterized and closed until the following summer. They are formulated to last up to 5 months but are less effective during the summer months.

Best Pool Winter Algaecide Recap

While there are many different algaecides on the market, only winter or long-life products will protect your pool from algae while it is closed and out of action during winter. Whether you choose a more expensive, safer polyquat or a longer-lasting, less costly copper-based version depends on which fits your requirements, but I’ve highlighted a few of the best of each to make your decision easier.