Print full article

Lengthening the swim season: Using liquid pool covers to reduce evaporation and conserve heat

Preventing water evaporation is one of the most cost-effective ways a homeowner can reduce unnecessary top-offs, chemistry adjustments, and heat loss.

By Alicia Stephens

With so many new pool owners excited to get the most out of their new investment, liquid pool cover products are quickly becoming popular as a way for service technicians to open pools up earlier in the spring and extend the swimming season into the fall. Regardless of the temperature outside, liquid pool covers allow pool professionals to open their clients’ pools sooner, so homeowners can start swimming but still reduce evaporation and conserve the heat in the water.

Why should liquid covers be offered to all clients?

Industry professionals can offer consumers options that will make their new pool ownership experience very satisfying. The idea of getting a pool is to enjoy it, not to labour over it. Today, more than ever, pool owners are looking for products to help them do just this. Liquid covers are one of many products that can help improve the pool enjoyment process. These products can make a pool professional seem like a hero in the eyes of the pool owner as they realize they can enjoy their pool much earlier and later into the season, while reducing maintenance costs at the same time.

What is a liquid pool cover?

A liquid cover is an evaporation suppressant that creates an invisible barrier at the surface of the pool to help trap heat and reduce evaporation. These products create monomolecular layers, or barriers, primarily composed of cetyl alcohol, stearyl alcohol, or ethyl alcohol (ethanol). The product is added to the skimmer with the circulation system running to disperse the monomolecular layer on the surface.

When explaining how these products work to customers, pool professionals can use the analogy that it is like putting a lid on a pot of boiling water. The layer is a single molecule in thickness and creates additional surface tension. It contains fatty alcohols that readily float on the surface to block direct interaction between the air and the pool water. Dispersants are also used in the formulas to spread the material across the surface of the water.

This type of technology was originally tested and applied in the drinking water reservoir industry. From its use in this industry, it was learned the combination of both cetyl and steryl alcohol was highly effective at reducing evaporation. In fact, both ingredients are found in numerous cosmetics and detergent products, as well as being used for food preservation.

A liquid cover creates an invisible barrier at the surface of the pool to help trap heat and reduce evaporation. Photo courtesy Biolab

How does a liquid pool cover work?

When liquid covers form the monomolecular layer on the pool water, extra surface tension is created on the water, helping to prevent the release of water vapour into the atmosphere. While the surface tension is broken when swimmers are present, the tight molecular arrangement of the layer causes it to quickly reform.

The beauty of using a liquid solar cover is that it is always above the water. The number one difference between a physical solar cover and a liquid cover product is a physical cover does nothing if it is sitting bunched up in the backyard. If someone forgets to put the solid cover on when the temperature drops on a cool night, there will be considerable evaporation loss. On the other hand, liquid solar products are always in the water if they are added consistently according to dosage instructions.

Leave a Comment


Your email address will not be published.