In Episode 298 of the Pool Nation Podcast, Edgar and Zac are joined by industry experts Robbie Walker and Michael Viegas from Solenis to break down one of the most misunderstood areas in the pool industry — spa, hot tub, and cold plunge water chemistry.

If you’ve ever treated a spa like a pool… this episode will change everything.

We dive deep into:

Why hot water chemistry behaves completely differently
The truth about biofilm, bacteria, and “human juice” in spas
The real differences between chlorine, bromine, and biguanide systems
How aeration, temperature, and bather load destroy your chemistry
Why your sanitizer disappears overnight
The rise of cold plunges and wellness systems
And how pool pros can turn spas into a profitable service category

This is a must-listen for pool service pros, repair techs, and anyone looking to level up their understanding of water chemistry — especially in smaller bodies of water like spas and hot tubs.

👉 Bottom line: If you're not treating spas differently, you're doing it wrong.

⏱️ Podcast Timestamps

00:00 – Intro: Welcome to Pool Nation Podcast
02:30 – Meet the Guests: Robbie Walker & Michael Viegas (Solenis)
06:45 – Why Spa Chemistry is NOT Pool Chemistry
10:20 – History of Spas: From Romans to Modern Hot Tubs
15:30 – The Rise of Cold Plunges & Wellness Trends
20:10 – The 3 Biggest Differences in Spa Water Chemistry
25:40 – Bather Load: The Truth About “Human Juice”
30:15 – Chlorine vs Bromine vs Biguanide (What Actually Works Best)
38:20 – Why Your Sanitizer Disappears in Hot Water
42:10 – Aeration, Jets & pH Drift Explained
47:30 – Shocking & Oxidation: What You SHOULD Be Doing
52:45 – Biofilm: The Hidden Problem in Every Spa
58:10 – Drain, Purge & Refill: The Right Maintenance Schedule
1:03:20 – Enzymes, Borates & Supplements (What’s Worth It?)
1:08:15 – Ozone, UV & Mineral Systems (Do They Replace Chlorine?)
1:12:30 – Final Thoughts: The Future of Spa & Wellness Industry

🙌 Special Thanks to Our Sponsors

A huge thank you to our Visionary Partners for supporting the Pool Nation Podcast:

The SPPA
Blu-Ray XL
AquaStar Pool Products
Natural Chemistry
Raypak
Heritage Pool Supply
Hayward Pool Products
Poolside Tech
Pool Brain
Nidec
OnCore Filtration
EnCore Brands

We appreciate your continued support in helping us grow the pool industry and build a nation of pool pros.

E-298 Pool Nation Podcast Hot Tub & Spa Chemistry Masterclass: Why Pool Pros Get It Wrong (Hot Water, Biofilm, Bromine & Cold Plunges Explained)