There exists today a gulf between the systems that commercial entities use to maintain swimming pools and those that homeowners use, and Alvaro Alliende, the head of a California startup called Drop, is trying to close that gap via a solar-powered, Wi-Fi-connected temperature, acidity and chlorine sensor designed for use in residential pools.
“For commercial [or institutional] pools, sophisticated equipment is used that measures chemistry levels and injects chemicals into the pool automatically,” Alliende says. “It takes a lot of space—the main control unit is the size of a big couch—and these systems cost around $1,500 and above.”
Maintaining family pools, on the other hand, generally means using a small chemistry set to analyze water samples to determine the mix of chemical inputs needed to balance the pool’s chemistry. It’s a cumbersome process and one that Alliende, who is currently finishing his MBA, as well as a master’s degree in public policies, at Stanford, says is far from foolproof.
Alliende co-founded the Bay Area startup with Stanford cohort and engineer Fernando Zavala and Emmanuel Laffon de Mazieres, an industrial designer with Lab126, a technology-development group at Amazon. The company is a third of the way through its effort to crowd-fund the pool-management system on Kickstarter—though not quite a third of the way to its $100,000 goal.
When a homeowner purchases a Drop unit, Alliende explains, she places it in the pool and installs the Drop application on her phone. The app detects the unit’s unique ID number and authenticates it so that both the phone and the unit are paired and their identities are transmitted, through the Internet via the Wi-Fi network, to Drop’s cloud-based servers. (Each additional user in the household must also download the app and pair his or her phone with the Drop unit in the same way.) The unit then begins transmitting temperature, acidity and chlorine readings to its cloud-based server, via the Wi-Fi router. Whenever the user opens the application, she can access the current readings, along with Drop’s suggestion for what quantity of each chemical she should add to the pool water.
Drop is not wading into empty waters. ConnectedYard , another Silicon Valley startup—this one backed with an undisclosed amount of venture capital from Burlingame, Calif.-base Tandem Management, and whose name hints at ambitions to connect more than just swimming pools to the IoT—just launched its own connected pool sensor, known as pHin. It does roughly the same things that Drop does, but connects directly to a user’s smartphone, via a Bluetooth connection.
Then there’s San Francisco-based Sutro, which launched earlier this year through Bolt, a combination venture-capital firm and technology incubator. Sutro takes the third option to connectivity: cellular. It sends sensor readings directly to the cloud, rather than through a Wi-Fi router or to a smartphone. In addition to measuring pH, chlorine and temperature levels, the Sutro device contains a salinity sensor, making it useful for people who have saltwater pools.
Sutro and ConnectedYard have a similar business model: Consumers don’t just buy the device—they join a subscription service through which each company ships the right amount of chemical additives each week, based on the chemistry of the pool according to the pool sensors’ output. Users are shipped only the amount they need, eliminating the need to store bulk amounts of dangerous chemicals in the home or garage.
Drop will offer a similar subscription service, Alliende says, but will not require that customers use it. It also has one feature that its competitors lack. A three-axis accelerometer inside the Drop device detects when someone has entered the pool, thereby triggering an alarm that users receive on their phones via the Drop app, as long as they opted to receive push notifications when they installed it. (The motion detected must exceed a set threshold, he says, so that it takes more than a strong gust of wind or a bird alighting on the pool to trigger the alarm.)
To avoid false-positive alarms, the motion alert can be turned off in the Drop mobile app before a person uses the pool. Alliende says he and the team are still testing options for how the safety system will re-engage after it has been deactivated. It may rely on the user re-engaging the alarm through her phone after everyone is out of the pool, or it might automatically reactivate after a given amount of time.
Of course, plenty of homeowners already rely on pool-cleaning services to regularly measure and correct the water’s pH and chlorine levels—an industry that market research firm IBIS World calls a $3 billion industry in the United States. It’s unlikely that a few IoT startups will disrupt that industry in the near term. But combining the sensing capabilities with a safety system does make Drop’s approach a novel one. (Pool-safety alarms already exist, but they trigger alarms only at the pool and in the home, Alliende says, and do not send an alert to a smartphone.)
All three products also work in hot tubs—which, according to the Association of Pool and Spa Professionals, actually outnumber in-ground pools in the United States. There are 5.8 million hot tubs, the organization says, compared with 5.1 million pools.
The Centers for Disease Control and Prevention reports that dirty or unbalanced pool water led to 5,000 emergency room visits for skin or gastrointestinal complaints in 2012, and ConnectedYard is using that statistic to compel homeowners to buy its product. But water-savings are another come-on, since well-maintained pools and spas require fewer flushes. So it’s possible that with the drought starting to drive water prices up in California, the biggest U.S. market for pools and spas of all types, IoT pool-management systems could strike pay dirt.
An earlier version of this story said professional pool management systems cost $15,000. The actual cost is approximately $1,500. Also, it noted that Drop is not using a subscription model. In fact, it will offer one but will not require that customers use it.