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How do I know if my ozonator is working?


Susanj

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The new service person for our hot tub at our vacation rental thinks the ozonator isn't working because he didn't see bubbles and asked me to call the company we bought it from 9 months ago. This is one thing I know nothing about. I hear the filtration system cycle on and off. So I pulled out our manual and it said the ozonator only works during the filter cycle.

He had checked it when the filtration system wasn't running. But how would you be able to see the bubbles when it IS running?! 

Speaking of which, how often should you set the filter to run? I thought I read 6 hrs a day somewhere and my manual says the default is 60 minutes on and 12 hours later, 30 minutes on.

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First of all, it's true that the ozonator only works during the filtration cycle. 

The ozonator doesn't actually create bubbles.  It converts oxygen into ozone by pulling air across an ultraviolet bulb or corona.  One end of the ozonator has an open port that acts as a source for air.  It's basically just a hole in the case.  The ozonator is then attached by plastic tubing to an ozone injector, which is a fitting in the circulation line that sucks the air in that plastic tube into the water that's being circulated.  There is a one way air valve in that tubing to prevent water from backing up into the ozonator when it's not circulating.  You can look up the term "Venturi action" if you want an explanation of the principles behind it.

If the ozonator is not working, there's just oxygen and air in that tube, and it will still get sucked into the circulation line and you'll still see bubbles.

No bubbles means no water circulating or an obstruction in the tubing.

Since ozone is an invisible gas, it's pretty difficult to tell if the ozonator is working.  The ultraviolet bulb (or corona) has a limited life span.  Usually a year or two.  Depending on the hot tub and the installation, you may be able to see a purple glow from the ozonator.  There are companies that sell test strips for ozone but they are expensive and unreliable.  Ozone has a very short lifespan, it breaks down in minutes, so you can't take a water sample to be tested.

Ozone kills microbes and helps keep your water clean.  Signs of a non-functioning ozonator are water that suddenly is not clear, even though your disinfection cycle hasn't changed.  Sometimes, the one-way valve sticks open and water gets sucked back into the ozonator, shorting it out.  That will often cause the hot tub to short out, although that's not always the case. 

New model Jacuzzi and Sundance spas try to get you to change the ozonator bulb every 12 months, but most hot tubs don't go to that extreme.  If your ozonator was 4 or 5 years old, I'd say it's probably not working.  At 9 months,  it should be working.

A typical filter cycle is 2 hrs on followed by 10 hours off.  It depends on where the tub is.  If you have lots of pine trees around, the needles will constantly be getting into the tub so you need a lot of filtering.  If it's an indoor hot tub where the only dirt is from your bathers, you may be able to reduce the filtering time.  The cost of running the pumps for filtering is very small.

Remember, your hot tub is also filtering when it is heating water. 

 

 

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 is the filtration system that cycles on or off basically just the jets automatically coming on?

I'm guessing by your question that your filtration is performed by your jet pumps and not a separate circulation pump, which is very common.

The purpose of the filtration is to draw water through the filter, the fact your jets are coming on is due to how the plumbing is set up in your tub.

As to  your question about test strips, I don't know how to answer that.  If you're not using Bromine, yes, you'll have a lower reading on your test strip.  But if your tub has been operating satisfactorily for the past 9 months, I wouldn't go changing things just because some guy on the internet told you something.

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I'm assuming then that it's like you said-that filtration is performed by the jet pumps coming on , because I have never seen any button to start the filtration system , just start the jets manually.

 

 It wasn't one person on the Internet who said that -I seem to have read that several places but cannot find it now , that if you have an ozonator, whether you're using bromine or chlorine, you look for a lower reading like 1 to 2 instead of 3 to 5 or something .

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Having an ozonator means you can get by with less sanitizer "

It was from hottubworks.com-

 

Build a bromide bank first, of 10-15 ppm of Sodium Bromide  , shock the spa, and then add a few tablets to a bromine floater to maintain a bromine residual of 3-5ppm (or 1-3ppm for Spas using mineral purifiers or ozonators).

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Greetings Susanj, yes you are correct when the jets are running is when the filtering is going on for most spas.  Note that some spas are equipped with a low-flow circulation pump aka "circ pump" that can filter all the time without the jets going.

You are also correct that the ozonator can reduce the amount of oxidizer (chlorine or bromine) that you use.  This is because ozone is capable of breaking down contaminants in the tub the same way as chlorine or bromine.  So some percentage of the stuff that would ordinarily be broken down by chlorine or bromine, will get taken care of by the ozone and thus reduce the amount of chlorine or bromine that you spa uses. 

It is important to notice that it "can reduce", not that it "will" reduce.  As other posters pointed out, it can be difficult to tell if the ozonator is working even if you do see bubbles flowing into the spa.  Then there is a whole nother debate on how much effect the ozone from an ozonator really has.  About the only real indication you have that they work, is that sometimes when they fail people will notice that their chlorine consumption goes up.

 

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