Pool Controller and Spa Controller – AquaSense

Do you want stable chemical control and an odor free bathing environment for the users of your pools and spas? If so the AquaSense from Pi addresses and resolves the issues that plague swimming pools and spas, such as; overdosing of chlorine leading to odors and excessive chemical usage, poor pH control leading to sore eyes and complaints, and periods of low or zero chlorine residuals leading to bacteriological failures and problems with the local health authorities.

AquaSense uses the highest quality sensors and the latest in control algorithms to ensure that the chlorine levels stay where you want them to be, no silly spikes and troughs which means that you have a trouble-free pool or spa.

To find out more about AquaSense, get in touch with one of our technical experts today.

What is the AquaSense Pool & Spa Controller?

The AquaSense has been designed to three criteria:

  • The Best Chemical Control – the best sensors leads to better process control which leads to less variation in chlorine residuals, (even with highly variable bathing load), reduced chemical usage, and lower costs.
  • The Best Bather Experience – better process control means less variation in chlorine residuals, meaning you get reduced chemical usage, lower costs and the best possible bathing experience.
  • Reduced Costs – lower chemical costs, less expensive controllers, inverter control leading to hugely reduced electrical usage costs. These are just a few of the ways that the AquaSense can save you money which can pay for a new controller in just a few months!

To find out more about how AquaSense can improve your bathing water and save you money, get in touch with one of our technical experts today.


The smell often comes from chloramine, which occurs when the chlorine in your pool combines with substances such as oils, sweat and skin cells from bathers in your pool. It can also occur if you are overdosing your chlorine.

By utilizing a good controller such as the Pi AquaSense, and the correct dosing equipment. Feel free to contact us to discuss your pool and find the best solution.

Adding chlorine to the pool or spa will oxidize substances in the water, such as oils, sweat and skin cells, killing any organisms. The chlorine left after everything is oxidized is the residual chlorine.

Adding chlorine to pure water (pH4 – pH11), results in a chemical reaction. This forms hypochorous acid (HOCl) and hypochlorite (OCl). Together, these make free chlorine.

Combined chlorine is the collective name for three chloramines; monochloramine, nitrogen trichloride and dichloramine.

Monochloramine is formed in water containing ammonia and hypochlorite.

Nitrogen trichloride is formed in acidic solutions when monochloramine disproportionates.

Dichloramine is the chloramine smell that is usually mistaken for a chlorine smell. This often occurs where there is a low concentration of chlorine.

Total chlorine is free chlorine and combined chlorine together.

Yes. However the effect is minimal and most users accept this as standard.

Using a handheld colorimetric DPD meter.


In the modern and busy world of the commercial pool, operators don’t have time to check up on equipment and write down or download data from pool controllers. That’s why AquaSense comes with some remarkable abilities. Not only can it datalog any signals you decide to put into it but it can;

  • Text or email alarms
  • Automatically put the process into “Safe Mode”
  • Push “live data” into the cloud so it can be available anywhere at any time
  • Automatically create reports and email them
  • Be setup remotely so if you get stuck we can be there in plant room with you.

Many leisure facilities are now fitted with sophisticated BMS (Building Management Systems), and Pi’s pool and spa controllers can communicate directly to the BMS, whatever system it may be by using a range of communication protocols including LAN, Profibus, Modbus, and MQTT as well as more traditional analogue and digital outputs.

By turning down the pool recirculating pumps overnight AND when the pool is less busy, it is possible to save a lot of money on electricity, especially during the day when electricity is more expensive. The CRIUS®4.0 has algorithms that allow you to control an invertor which in turn controls the speed of your pumps.

This works because most pumps are over specified for the duty (they are too big) and so we can turn them down to the minimum flow specified by the installer of your pool. As long as you don’t go below that flow you can save money and pay for your new controller in a matter of months. Not only that but by using less electricity you are reducing CO2 emissions and helping to save the planet.

Focus On

Focus Ons are a series of short articles, providing technical information regarding instrumentation, process measurement in potable, waste, process and pool waters. If you would like to join the mailing list, please contact us.


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