The chlorine shortages we’ve been facing this pool season has consumers looking for viable alternatives to a traditionally chlorine sanitized pool. Natural pools first started as a trend a few decades ago in Europe and over the past few years have slowly been gaining traction in the United States and Australia.

What is a Natural Pool?

A natural swimming pool typically doesn’t use chlorine for sanitization. NSP’s use plants to filter the water chemistry naturally, without chemicals. In most applications, the swimming pool is divided into two different sections: an area for swimming, and a dedicated regeneration zone with living plants that feed hydroponically on the water.

How does a natural pool work?

The water itself is naturally filtered by microorganisms through biological filtration plant life in the regeneration zone. The water is cleaned and filtered as it passes through the regeneration zone, and then back into the swimming area. A pump allows slow moving water to passively filtrate and the movement helps prevent mosquitos from breeding.

Small aquatic animals, such as microscopic algae-eating daphnia, snails, and amphibians, will typically colonize the regeneration zone of a natural pool environment over time.

Natural Pools Are Becoming More Popular

Allen Schnaak, Vice President of Business Development for BioNova Natural Pools thinks this could actually be a pivotal moment to introduce the pool industry to a new way of looking at how to filtrate and treat bodies of water. Recently Schnaak spoke with the Wall Street Journal touting the virtues of a chemically independent pool environment, and suddenly folks have begun to seriously pay attention.

No chlorine? No problem. This summer, homeowners are trading traditional pools for natural pools, which are chemical-free. https://t.co/r2uoH5VJWA

— WSJ Real Estate (@WSJRealEstate) June 25, 2021

BioNova is one of a handful of companies around the United States that are specializing in building NSP’s (natural swimming pools). Schnaak, who has appeared in numerous articles on the subject, has been working to educate consumers as well as the pool industry about the benefits of bio filtering swimming pools without the use of chlorine or other chemicals.

The Value Proposition of owning a Natural Pool

“Biological filtration in a natural pool has the same objectives as chemical applications.” said Schnaak who has a long history in the pool industry and worked on the chemical side before embracing natural pools. “The purpose of adding chemicals to the pool,” continued Schnaak, “is the same purpose of biological filtration and that is to reduce and suppress the opportunity for pathogens to exist and thrive in the water.”

“We’re seeing this play out in natures backyard in Tampa Bay right now with the red tide influenced by a greater amount of nutrients than the ecosystem can consume which gives these pathogens an opportunity to thrive.” said Schnaak referring to a toxic algae bloom which has ravaged marine life and killed millions of fish over 100 square miles of Florida coastline.

We’ve seen plenty of articles discussing natural pools, how they work, and why consumers should consider building one. In my discussions with Schnaak prior to our interview, I asked him if he would be willing to have a frank and open conversation with Rudy Stankowitz who has openly expressed his disdain for natural filtration and disaffectionately refers to NSP’s as “ponds”. Schnaak jumped at the opportunity to address Stankowitz one on one on the Pool Magazine podcast.

The timing for Schnaak to pitch the value proposition for natural pools couldn’t come at a better moment. With the current shortages consumers are facing, plus a new emphasis on eco-consciousness, the opportunity is there for bio pools to pick up enormous traction. The problem however, is winning over the pool industry. Folks like Rudy Stankowitz, one of the foremost experts in swimming pool algae have their own ideas about how viable bio filtration truly is in comparison to using chlorine.

“It is not necessary to chemically treat a pool in order to make it viable and healthful for someone to swim in.” said Schnaak, “Our opportunity in the market has certainly increased, and we’re definitely anxious and interested in getting more of our pool industry cohorts to consider that there is a viable option outside of chemical treatment.”

An Opportunity To Convince Non-Believers

Stankowitz, who recently authored a new book “How To Get Rid of Swimming Pool Algae“, has appeared on the Pool Magazine podcast when we discussed the chlorine shortages and the trajectory this years supply chain would take. Extremely knowledgeable when it comes to swimming pool chemistry, Stankowitz is a 30 year veteran and CEO of Aquatic Facility Training / CPOClass.com.

We felt that having Schnaak and Stankowitz go head to head would make for a compelling dialogue and we weren’t wrong. Stankowitz’s expertise and viewpoint create the perfect counterpoint for a dynamic conversation about natural pools. Schnaak and Stankowitz go way back and have a mutual respect for eachother, but currently they sit on opposite sides of an important issue. Whether natural pools are as safe to swim in and ultimately as cost feasible as chemically treated pools.

“Really, I’m not a fan” said Stankowitz, “I am a fan of algae being used for other things. Things are progressing, there’s been a lot more fuels. Even in waste water treatment, algae has become a major player. My problem is that this is basically a pond and it looks like a pond.”

“As long as anything living gets into it, there is going to be constantly things that are introduced to that body of water that are not able to be eradicated quick enough that it can’t cause a potential problem for human beings. The follow up to that which is just as heavy is water clarity. We know that 10% of all drownings are attributed to cloudy water situations.” said Stankowitz.

“The preconceived notion that all natural pools are green messy bodies of pond water are just a misimpression. We’ve done pools with water clarity easily down to 12 feet. I’m a big believer in safe water environments. In fact the swimming pools we design are built to ICC and ANSI standards. The vessels are safe, and to that point water clarity is not an issue.” said Schnaak.

“If your only experience with a natural pool is looking at a green cloudy pond, then there’s a greater exploration of opportunity. We’ve got a 20,000 square foot public pool up at Webber Park with a 13 foot diving well that is totally clean with a 500 person bather load.”

• Swimming pool is 21,000 sq. ft. (500,000 gallons water)
• Regeneration basin is approximately 16,250 sq. ft.

“The Opportunity Is On You”

Stankowitz replied “We’re giving you the benefit of the doubt. The opportunity is on you…” in reference to changing perception in the market that not all natural pools are ponds. “I’ve only seen the pictures that people put out there and honestly I have never in any magazine, in any post or anywhere seen a natural pool that is not green. So the opportunity for education is on you. I’ve known you a long time and I believe you.”

“From the standpoint of the industry and where it is in the United States, natural pools are not nearly as prevalent in the U.S. as they are in Europe. 16% of the recreational water in Europe are natural swimming pools. Probably less than 0.3% in the U.S. can be termed as a natural pool.” said Schnaak.

“The opportunity for helping the industry recognize that this is a viable method for maintaining recreational water is on us, you’re right; and it’s really up to the market as well. There certainly is an increasing interest by those looking for more sustainable options for pool care.” continued Schnaak.

“The opportunity for nutrients to be put into a body of water is going to be defined by the footprint that it has in the landscape.” said Schnaak. “As any pool is constructed it’s always built so that it does not allow surface runoff to enter the pool.”

Debating The Safety of Natural Pools

“We do know that with a given square footage there is an anticipdated amount of environmental depositions of nutrients that are constantly bombarding the pool.” said Schnaak, “In a chemical environment they are referred to as contaminants because everything that can be oxidized, reduced or killed has to be killed as soon as you begin taking out the beneficial microbial life that would be consuming it.”

“I don’t necessarily know that I agree with you that if you have diatoms present in a body of water that you will not see cyanobacterial biofilm.” said Stankowitz.

“I understand the process that we’re feeding the water with phosphates and silicates so that diatoms can outgrow and use up the nitrates so that nothing else can have them therefore they don’t grow. In theory, that works great. The problem is just like there are carbon fixing diatoms, there are nitrogen fixing cyanobacteria so you will still have these biofilms, and these biofilms do harbor many other disease causing organisms such as Legionella and Naegleria fowleri (the brain eating amoeba),” continued Stankowitz.

“I’ve done extensive studies on black algae which is cyanobacteria and in those biofilms I’ve found diatoms living happily. It’s not an incompatible relationship if you have the right diatoms and the right cyanobacteria.” said Stankowitz.

“It’s interesting that diatoms are a participant,” responded Schnaak, “they are part of the population, but they are not the only microbial life. When you consider phytoplankton, zooplankton, the entirety of population of beneficial bacteria that has been specialized for the nitrogen reduction cycle.”

Schnaak suggested that copepod zooplankton like Daphnia which grazes in fresh water environments on cysts like Cryptosporidium and Giardia and harmful viruses to which Stankowitz responded with a few different “what if” scenarios. “To your point about Daphnia, it feeds til it explodes and releases that back into the water. That’s also the problem we are having with the red tide. Daphnia doesn’t last long enough to contain it all and then if it’s consumed by an animal, a person can eat that animal, or it can be defecated or released into the atmosphere and that could make it’s way back into the pool.”

Changing Perception That Chlorine Is King

“I think the major challenge for you,” Stankowitz said to Schnaak, “is chlorine does kill these things. We have proof that chlorine kills those things. What we need then if this is true, if this system takes all these things out, we need to get that research out and make that common knowledge because that’s how you gain more acceptance in the pool industry,” continued Stankowitz.

Schnaak agreed and said that as a member of the council for the Model Aquatic Health Code that they’d begun participating in an ad-hoc committee for the evaluation and potential implementation of biological filtration for public aquatic venues. Schnaak agreed there is much that is still misunderstood about natural pools and that each project has to account for the specific environment, size, bather load and unique characteristics.

No One Size Fits All Solution

Natural swimming pools are very dependent on maintaining ideal conditions for the plant life which bio filtrates and allows useful organisms to thrive. “There isn’t a one size fit’s all, neither is there in chemical applications. There’s not a pool out there where you couldn’t find a pathogen or organism living in that environment. The presence of chlorine does not indicate a sanitized environment.” said Schnaak.

Ultimately, Stankowitz still had serious questions pertaining to how long harmful pathogens can survive in the biofilm in a natural pool and insists that chlorine is still the most reliable solution for sanitizing pools. Schnaak is adamant that the system that BioNova has created is capable of biologically filtering swimming pools to the point where they are viably safe swimming environments.

Stankowitz said that while he’s open minded to the concept of natural pools, he needs to see more conclusive research on the subject before he’s swayed from using tried and true chlorine sanitization methods, which prompted Schnaak to invite him and as well as others interested in learning more about natural filtration methods, to seek out more information on the Association for Swimming Ponds and Natural Swimming Pools website.

Why Have Natural Pools Been Slow To Catch On In The U.S.?

While natural pools are becoming increasingly popular in Europe, there is no denying that they have a nominal marketshare in the United States. In this humble editors opinion, there are several impediments towards more acceptance beyond those early adapters.

One is the public perception that all pools must have crystal clear blue water. Another are the requirements for constructing a natural pool. Given the need for an additional regeneration zone, most natural pools are typically built on larger sized lots. The initial build and configuration cost for a natural pool is also much more than your typical inground pool. There is definitely some give and take in terms of initial cost concerns versus ongoing chemical costs.

There are also a good portion of consumers that while aware of natural pools, have a tendency to believe a popular misconception; which is that NSP’s maintain themselves. Natural pools, just like chemically treated pools still require routine maintenance and to some extent even more attention than a chemically treated pool in order to ensure a harmonious water environment.

Still Schnaak remains a champion for the bio filtration cause and says a growing percentage of environmentally conscious homeowners yearn to go chlorine free. As such, he will continue to facilitate and fan that interest to generate more excitement and awareness about natural pools.

Q&A Fact Sheet About Natural Swimming Pools – NSP’s courtesy of Allen Schnaak – Vice President of BioNova Natural Pools

Listen to our entire interview with Allan Schnaak and Rudy Stankowitz on the Pool Magazine podcast.

Featured Photo Credit & Article Photo Credits: BioNova Natural Pools