We have talked before about getting the right sized ozonator for your spa, focusing mostly on the size of the tub. In this post, we want to highlight another part of the puzzle that can make a big difference: your pump function.

Hot Tub Volume: The Basic Requirements

Just to reiterate, the ozonator you need for your hot tub or portable spa has to be big enough to handle the water volume. DEL offers three standard replacement ozone generators which serve hot tubs in two tiers, those up to 500 gallons and those between 500 and 1000 gallons. (Ask DEL about larger tubs or wave pools: units are available.)

CDS-16: Sanitizes hot tubs up to 500 gallons. A chip-based Corona Discharge (CD) ozonator with   ozone output rated at 35 mg/hr. 110V only.

Spa Eclipse: Sanitizes hot tubs up to 500 gallons. Chip-based CD ozonator with 35 mg/hr output. Visible ozone monitor and available in dual voltage (110V/220V) model.

MCD-50: Sanitizes hot tubs up to 1000 gallons. Sealed electrode CD ozonator capable of 50 mg/hr ozone output, typically capable of 5 years life before refurbishment or replacement.

Other manufacturers may have similar models.

Circulation Pump Operation is the Wild Card

Here’s the new stuff. The ozonator is working ONLY when the circulation pump is running. That’s because the ozone is drawn into the water circulation by a vacuum created at the point of injection by the injector device. At this point, the ozone is dissolved in the water and is an effective disinfectant.

The key thing here is that the vacuum is created when the pump pushes water through the injector under pressure. No pump action, no ozone.

So it’s easy to see that the timing and duration of your pump cycles makes a difference in the amount of sanitation and disinfection your ozonator is capable of producing. In today’s energy-efficiency environment, you may have reduced your pump cycles to save money and energy, but in the process you may have reduced your sanitation to the hot tub as well. You can compensate for this by adding more chemicals, but that defeats the purpose of having a simple, effective, low-chemical sanitation regime for your hot tub.

Design Your Pump Cycle to Optimize Sanitation

Instead of reverting to chemicals, here’s a couple suggestions for getting more sanitation out of your ozonator.

Run the pump (and therefore the ozonator) at least 6 hours per day. Pumping water through the circulation system this long is the basic turnover required to get the water in contact with ozone. In addition, it will ensure that the water flows through the filtration system enough to help maintain water clarity.

On older tubs with 24/7 low-speed pumps, make sure the ozonator is connected to this circulation line and that the injector is effective with the water volume flowing through the injector. If the ozone is being dissolved into the water stream at this lower speed, the sanitation is optimal.

Of course, there’s always another way to use the pump more. Get in the hot tub often!