How Simple, Safe, and Seamless Drove Our Design Process - Sutro, Inc

How Simple, Safe, and Seamless Drove Our Design Process

I came up with the idea for Sutro based on my experience working in my dad’s pool business. It was obvious to me, since I worked at it daily, that testing pool and spa water was a major pain. We would have countless customers come into our shop asking us to test their water. It was clear that it was one of the hardest things to get right and even harder to do consistently.

Learning Can Sometimes be Painful

Sutro’s first attempt at a smart monitor was back in 2015. We designed a product that was similar to what’s out on the market now — glass-bulb-based testing. I won’t bore you with a big technical rant on that. Let’s just say that the painful lesson we learned is that glass-bulb-based testing has a horrendous drift problem. That drift causes the results to vary over time, greatly — thus making it impossible to provide an accurate recommendation. Garbage in equals garbage out.

That’s why we choose to use reagent based testing for our new design. Reagent-based testing using reagents or chemicals to turn the water different colors. If you have used a Drop Based Test Kit where you drop reagents into water from little bottles, then you have been doing reagent based testing like we do.

Reagent Based Testing is the Gold Standard

Our reagent-based testing technology is based on our partner’s, LaMotte, 100 years of experience. LaMotte’s testing technology is used to determine the quality of drinking water since it’s the most accurate and repeatable method out there. The other advantage of reagent-based testing is that drift is nonexistent since each and every batch of reagents is testing to a standard and certification. Since our Smart Monitor uses about a cartridge of reagents each month, this ensures the most accurate results. We want to make 100% sure that the readings we send to our recommendation engine are as accurate as possible. Think of our Smart Monitor as a little floating water lab that uses the same method that the EPA uses to ensure drinking water is safe. 

It All Starts With (Potential) Customers

Back in 2015, we made another mistake in designing our monitor that turned out to be on par with the glass bulb design decision — not getting early and frequent feedback from customers.

The culture in Silicon Valley is one of moving fast and breaking things. Most technical founders, myself included, figure that with whatever whizbang gizmo we could invent, our customers would be overjoyed. I mean, testing pools and spas is a major reason customers would come into my dad’s shop. Heck, I was a pool boy with an engineering degree and I hated it. What could go wrong?

The problem with designing anything is that we make a lot of assumptions that seem reasonable but end up taking you down endless rabbit holes. Two of the most painful rabbit holes were pool chemical calculators and determining which pool and hot tub chemicals people use to treat their water.

Pool Chemical Calculators

The heart of any good pool monitoring system is its pool chemical calculator or, what we call, our recommendations engine. Pool water testing is complex in that there are so many variables impacting a pool’s pH level, Free Chlorine, and Total Alkalinity. When those values are outside an optimum range, the results are cloudy water or green water, among other things. On top of that, it’s hard to test a recommendation engine given variables such as pool size, water-based chemistry, and geographic location. 


That’s why I knew we needed to develop Sutro AI to help us train our recommendation engine ahead of releasing our Smart Monitor. You can try it out by signing up here and simply text us your pool readings. Over the last couple of months, we have learned a megaton of information and squashed some major bugs. All of this will give us a much-improved pool chemical calculator that will provide our customers with the best results. What’s also interesting about Sutro AI is that it can give you recommendations based on the chemicals you use rather than those from a small menu of pre-packaged ones. That was one rabbit hole we managed to navigate around and emerge victorious.

Pool and Hot Tub Chemicals Aplenty 

My estimate is there are about 5,000 different types of pool and hot tub chemicals from which to choose. If you’re surprised by this, you’re not alone.  To be fair, the majority of those 5,000 are just different labels, concentrations, or sizes of the big four of pool chemicals: Bleach (Chlorine), Bromine, Muriatic Acid, and Baking Soda (Sodium Bicarbonate). I exclude salt water pools from this list because they are relatively new and those systems act like Chlorine but they do add to the 5000 list.

Being able to recommend a particular chemical to a particular customer requires that we know what said chemical does. That turns out to be a tough problem; one that we were attempting to solve, four years ago, by making our own chemicals. Well, we drowned in that idea. 

It turns out that it’s impossible to develop a smart monitor and chemicals simultaneously because there are so many variables needing to be taken into account. We learned that there is a good reason for the 5,000 or so pool chemicals out there and it’s not just marketing.

That painful lesson drove us to design our new system to use any chemical a customer might have. This, at first, may seem like a harder problem to solve but, as it turns out, the hardest part is simply getting started.

Block and Tackle Chemical Onboarding

We have been lucky in that our Sutro AI engine gave us insights into the exact chemicals customers were using. In turn, this led to an expanded effort to capture the names and UPC codes for those chemicals. It’s a manual and tedious process to undertake, but looking at all those names and UPC codes has allowed us to seed our recommendation and application onboarding with the most popular chemicals used to treat pools. Over time, it will continue to improve as the number of people who use it, continues to increase

Simple, Safe, and Seamless Was Not so Simple

It’s been almost five years since we started Sutro. It’s been a long and painful journey but, I must also say, a fun one. It’s amazing what a dedicated and talented group of people can do to change the way we will test our pools or spas. The turning point for me was when we hit on the idea of Simple, Safe, and Seamless to drive our design process. Before, we were chasing the notion that if you build it, people will come. In fact, our crowdfunding campaign proved that people were interested but it was harder than we thought to execute. With our new design, we have overcome those obstacles and are excited to get our smart monitor on the market.

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