Anyone have AOP/Spa experience?

[magisimo]

Hi,

 

I've spent a few days reading all the stickied (and other) posts here.  I haven't been able to find much on my question searching the forum, so I'm hesitantly posting a new thread..

 

I'm a first time spa owner with a new TidalFit swim spa (1,600 gallons) about to be installed.  It comes with an AOP combined with a Nature2 system.  There doesn't seem to be much info on AOP systems out there that discuss chemical dosing in any detail.  I understand that it is an ozone system plus UV to create hydroxyl radicals.  The configuration reduces the amount of ozone that ends up in general spa water, which prevents cover degradation, etc from the off-gassing.  'm assuming a lot of this is marketing, but i've read that it does mean i can use a lower amount of chlorine/bromine to keep my system safe.

 

I was planning on following the sticked thread from @waterbear which details out quite thoroughly how to keep my system balanced with bromine.  Some questions:

1) There seems to be debate as to whether bromine is compatible with Nature2.  Nature2's website itself states that it is, but there are many posts throughout different web forums stating otherwise.  The Nature2 manual states to use chlorine, but also doesn't mention you can't use bromine.  Any specific thoughts here?  I am fine going with chlorine if that's better/necessary.

2) Is it true that I can use a lower resting level of bromine/chorine and still have an effective/safe system with the AOP running?  Something in 1 ppm range?  It's my understanding that the AOP system is not the same as a standalone ozone generator as the end result hydroxyl radicals and not a long tube of ozone-injected water.  An AOP system is purported to actually reduce the need for standard levels of sanitizer.

 

Any other comments on AOP for the spa in general?  I know the swim spa capacity at 1,600 gallons will require 4 times+ more chemical than a standard spa, and i'm hoping the AOP system means I can use 1/2 that or less compared to a standard sized spa without an AOP system.  Or is this all marketing crap and I should use the standard chemical rates....?

 

Thanks in advance...

- Mike

[waterbear]

7 hours ago, magisimo said:

There seems to be debate as to whether bromine is compatible with Nature2

It is NOT.

 

7 hours ago, magisimo said:

Is it true that I can use a lower resting level of bromine/chorine and still have an effective/safe system with the AOP running

I wouldn't. AOP uses UVC and ozone but the problem is that neither are residual sanitizers and they only sanitize the water passing through the reaction chamber. The main body of water is NOT being sanitized. They are useful as an auxiliary sanitizer but you still need a fast acting EPA approved sanitizer in the water. Nature 2 is basically a silver nitrate cartridge that adds silver ions to the water. Silver has very slow kill times and no effect on viruses so you still need to have chlorine (or in a hot tub MPS water at 100 deg F or higher will work but you still need to shock with chlorine weekly) Silver is useful in drinking water treatment where the water sits in a closed system for a period of time so the silver can destroy microbes but a tub , swim spa, or pool is an open system that constantly has pathogens and organic matter added to it by the bathers. The smaller the volume of water (small hot tubs) the less forgiving and sanitizer can get depleted quickly.

Here are some fun facts that explain why you need a fast acting residual sanitizer at normal and not reduced levels. UVC and ozone are useful as additional insurance but ozone does tend to destroy chlorine and increases your chlorine demand and UVC has different properties, depending on the wavelength. Some wavelengths are very effective at destroying chloramines and volatile oxidation byproducts and others produce ozone. Bottom line, AOP does not replace a sanitizer nor does it allow you to run lower sanitizer levels no matter what the marketing hype says.

Fun facts (courtesy of Taylor Technologies):

The average person involuntarily urinates about 5─10 mL in pool/spa water.

The average person involuntarily releases about 10─25 mg of fecal matter in pool/spa water.

Fun fact (courtesy of Aqua Magazine):

The average person brings 100 million bacteria into the water. These join other living organisms such as biofilm, parasites, virus, algae, mold, mildew and spores. Then we add swimmer waste such as blood, sweat and tears, urine, saliva, mucous and other bodily fluids

The average spa user sweats up to three pints per hour at 102 degrees Fahrenheit.

Fun fact:

The chemical makeup of sweat and urine are almost identical.

 

7 hours ago, magisimo said:

An AOP system is purported to actually reduce the need for standard levels of sanitizer.

 

[RDspaguy]

14 hours ago, magisimo said:

An AOP system is purported to actually reduce the need for standard levels of sanitizer.

It will reduce the levels of sanitizer, in the sense that it will burn off chlorine. It does not really reduce the amount that you will add in the first place.

I like ozone and uv, and nature2, but there is alot of confusing info out there. I research studies from other industries, not put out by manufacturers trying to sell you on it. The hard facts about what it does are there to be found and irrefutable, imo, but it's effectiveness in a spa environment is what is being argued. Many of those studies are suspect.

My theory is, the more layers of protection the better. Especially if you are lazy or casual about maintenance. If you follow @waterbears method you will have no need for anything more, except maybe stock in taylor test kits. 😉

[magisimo]

Ok, understood on all points.

 

I think my initial plan will be to use the system with the AOP running and not use the Nature2 cartridge to start (as I would like to try bromine).  With the AOP system running, but still following sanitation standards, I'm going to shoot for a resting bromine reading at the 3-4ppm level (which seems to be the low-end of still-acceptable/normal levels).

 

Further questions:

- I've read that ozone generators can cause enough ozone that, after de-gassing, cover degradation may occur.  Does the AOP system lead to less of the ozone byproduct residual in the water and therefore reduce this harmful effect?  Is there anything I can do pro-actively to maintain the life of my cover?  I've got an End2End rollup cover (https://www.end2endswimspacovers.com/) on order as my physical disability requires something very easy for me to operate and I'd like to prolong its life as much as possible since it was quite expensive.

- I can't remember where I saw this mentioned, but I thought I saw something about floaters for bromine tabs not being recommended as they concentrate the bromine by the spa filters/equipment?  Is this an actual concern?

 

Thanks for the clarifications.

[RDspaguy]

On older tubs the ozone injection system left quite a bit to be desired, and it would eat covers like cheetos. I do not recommend replacing the ozone in anything pre-2005. On new tubs, it should not be an issue.

Tablet floaters tend to end up in front of skimmers and tablets are very low ph. Yes, it is a real concern over long term use, and is often visible in the equipment. I personally don't recommend tablets at all.

[magisimo]

Ok, seems like I've got all the info I need to start out.

 

Thanks very much guys.