Should i get UV/ozone ?

[randman19]

I have a uv system and from my understanding there are different levels of uv power. The ones for pools aren't as strong as the big drinking water systems. Also the flow rate through the system affects the effectiveness of the uv.
My water is crystal clear and I hardly use any chlorine. I have a 14k gallon pool and turn my water over 3 or 4 times a day. I run my pump at 1750 rpms which is about half speed 24x7. I like the system.

Hey @Bbisel55, I found your post on here and wanted to ask if you still have this system and if you are still liking it? I am thinking about this type of system for the pool I am building. I will also have an automatic pool cover, so a salt system concerns me with having all of that metal so close in proximity. Seems to be a lot of negativity towards uv ozone systems, but verdict is still out for me.

 

[Newdude]

Hey randman and welcome !!!

To have a safe pool, it needs to be sterile with residual sanitizer. UV and Ozone only sterilize the water in the unit, and only see already sanitized water if you're doing it right.

At best, it's entirely redundant.

If you don't plan on having sterile water, UV/ozone might help you as 'better than nothing'.

 

[an1vrsy]

Welcome to TFP! You seem to be under the impression that salt water chlorine generators, SWG, are no good for automatic pool covers. That is far from the reality. I have a SWG and a pool auto-cover. I have the Cover Pools T4 stainless steel auto cover. I have had it since March 2021. Hey, this Saturday is our pools 4 year anniversary.

Check out Cover Pools. The New T4 Automatic Pool Cover Mechanism and Motor for Stainless Steel Cable - Cover-Pools

 

[wireform]

Ah Ha, I guess you don't know that chlorine is also salt so if you plan on only using UV and ozone then salt will be distanced from the cover but, inorder to keep the pool sanitized there's something more then the ozone and uv that will be needed.

 

[PoolStored]

My pool water was 2000ppm Salt before I converted. Now it is 3200...not much difference.

UV Systems - Further Reading

www.troublefreepool.com

Ozone Systems - Further Reading

www.troublefreepool.com

 

[Dskrivan]

Hey @Bbisel55, I found your post on here and wanted to ask if you still have this system and if you are still liking it? I am thinking about this type of system for the pool I am building. I will also have an automatic pool cover, so a salt system concerns me with having all of that metal so close in proximity. Seems to be a lot of negativity towards uv ozone systems, but verdict is still out for me.

I have had a Paramount UV2 for 4 years now. I am about to convert my pool to salt pool and have decided to remove the UV. I have a friend that works at a pool wholesale and says they sell a lot of them....so this is just my opinion. I run my pool 24/7 so the bulbs only last about a year and a half. You have no way of know if the bulbs are good or not because they don’t burn out they just lose their effectiveness over time. Last time I replaced the bulbs and cleaned the glass housing for the bulb, I found was the tube was pretty scalely so not much light was getting though it and the bulbs had been black at the ends which means that were not really working….so I believe I had been wasting much on the electricity used to run it. If I had decided to keep it then I feel like I need to replace the bulbs every year if they are available, my friend said many just replace the unit every couple of years….Yikes. If I were having a pool built today, I wouldn’t invest in UV.

 

[midlifecrisis]

Hey @Bbisel55, I found your post on here and wanted to ask if you still have this system and if you are still liking it? I am thinking about this type of system for the pool I am building. I will also have an automatic pool cover, so a salt system concerns me with having all of that metal so close in proximity. Seems to be a lot of negativity towards uv ozone systems, but verdict is still out for me.

I built a pool two years ago. I installed it with UV/Ozone. It was ripped out and replaced with a SWCG about 8 weeks after water went in the pool. haven't looked back. It isn't worth it.

 

[wireform]

I have a a client that had UV installed at the build 10 years ago. When I took over the pool it was because the chemistry was out of control and that was 8 years ago. I've changed his UV bulb several times and was a major pain as for winter it needed to be removed (the whole unit) and stored inside. I got tired if it soon enough and told them it was time for SWCG. Fast forward, the RJ60 is working wonders for the last 5 seasons. I still have a brand new UV bulb that wasn't replaced and nobody misses it.

 

[JamesW]

UV and ozone are really only useful for high use indoor commercial pools.

Outdoor Residential Low-Use pools are not a good candidate for supplemental sanitizer systems.

Being covered might allow some CCs to develop and UV could help, but see if CCs are a significant issue first before considering UV.

Ozone needs a proper commercial system to be really useful and that includes contact tanks and offgassing equipment.

A residential UV-Ozone system makes tiny amounts of ozone and the ozone will trap under the cover and attack the aluminum rails of the autocover.

 

[JamesW]

When chlorine bonds to ammonia, it tries to oxidize the nitrogen by removing electrons, but the nitrogen holds on to the electrons and it is a slow process.

UV light is absorbed by the electrons and gives them enough energy to move from the nitrogen to the chlorine causing the nitrogen to convert into nitrogen gas and the chlorine to become chloride.

4NH₄⁺ + 3HOCl + 3OCl^- --> 2NClH₂+ 2NCl₂H + 6H₂O + H⁺ --> 2N2 + 6H₂O + 7H⁺ + 6Cl^-

4NH₃ + 3HOCl + 3OCl^- --> 2NClH₂+ 2NCl₂H + 3H₂O + 3OH^- --> 2N2 + 6H₂O + 3H⁺ + 6Cl^-

Organics are based on carbon and inorganic are based on non carbon atoms like nitrogen.

In swimming pools, organic chloramines form when chlorine reacts with organic matter, and these chloramines can lead to trihalomethane (THM) formation, which are disinfection byproducts potentially harmful to humans.

When chlorine bonds to ammonia, it tries to oxidize the nitrogen by removing electrons, but the nitrogen holds on to the electrons and it is a slow process.

UV light is absorbed by the electrons and gives them enough energy to move from the nitrogen to the chlorine causing the nitrogen to convert into nitrogen gas and the chlorine to become chloride.

4NH₃ + 3HOCl + 3OCl^- --> 2NClH₂+ 2NCl₂H + 3H₂O + 3OH^- --> 2N2 + 6H₂O + 3H⁺ + 6Cl^-

UV in sunlight or from a UV system will oxidize chloramines.

Monchloramine 245 nanometers
Dichloramine 297 nanometers
Trichloramine 260 and 340 nanometers.

The four Trihalomethanes are:

[CHCl3] Trichloromethane (chloroform) [3 chlorines]
[CHClBr2] Dibromochloromethane [1 chlorine, 2 bromine]
[CHCl2Br] Bromodichloromethane [2 chlorine, 1 bromine]
[CHBr3] Tribromomethane [3 bromines]

The EPA's most current regulations limit the concentration of these 4 chemicals added together (total trihalomethanes, or TTHM) to 80 parts-per-billion (ppb/µg/L).

The most common in chlorinated swimming pools: chloroform.

The carbon can be oxidized to carbon dioxide with a +4 for carbon like the burning of methane.

Organics are more persistent.

For a high use indoor pool, you need a supplemental sanitization system like ozone or UV.

I would use a good commercial grade UV system.

Some places are required to use a Secondary Disinfection System according to apsp-11_2019

https://www.phta.org/pub/?id=53c77806-1866-daac-99fb-e555a02ec432

https://www.in.gov/health/eph/files/How-To-Shock-The-Pool-2022.pdf

ANSI/APSP/ICC-11 2019 American National Standard for Water Quality in Public Pools and Spas

The ANSI/APSP/ICC-11 2019 American National Standard for Water Quality in Public Pools and Spas provides recommended minimum guidelines for the specifications for recreational water quality parameters in public pools and spas. An Appendix A includes explanatory sections about the values for the...

issuu.com

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The ANSI/APSP/ICC-11 2019 American National Standard for Water Quality in Public Pools and Spas provides recommended minimum guidelines for the specifications for recreational water quality parameters in public pools and spas.

An Appendix A includes explanatory sections about the values for the requirements listed in the body of the standard.

Based on health-related scientific information, this standard can be incorporated into national or regional health codes, and adopted by state and/or municipalities as a local code or ordinance.

 

[JamesW]

Most ammonia will be in the form of the ammonium ion, which is why the oxidation of ammonia is so acidic.

At typical pool pH, the percentage of ammonia will be less then 5% and more than 95% will be ammonium ions.

7/16 (43.75%) of the hydrogen ions are released as the nitrogen is oxidized to nitrogen gas.

4NH₄⁺ + 3HOCl + 3OCl^- --> 2NClH₂+ 2NCl₂H + 6H₂O + H⁺ --> 2N2 + 6H₂O + 7H⁺ + 6Cl^-

The pKa value for the reaction of ammonia (NH3) to form the ammonium ion (NH4+) is approximately 9.25.

Ammonia (NH3) is a weak base that can accept a proton (H+) to form the ammonium ion (NH4+).

The reaction is an equilibrium: NH3 + H+ ⇌ NH4+.

plot y = 100÷(1+10^(9.25 – x)) and y = 100-(100÷(1+10^(9.25 – x))), x from 7 to 11 - Wolfram|Alpha

Wolfram|Alpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.

www.wolframalpha.com

 

[JamesW]

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