Uv or ozone or both!!!

[Critrdoc]

Hello Folks,
I am so frustrated!!!! I have read and searched this amazing site to get myself educated on new pool ownership. I am in the thick of building an in ground pool, and my contractor "swears by" an ozone generator!! The setup they propose is an automatic chlorinator that uses trichlor tablets with a Clear O3 ozone generator placed right before the cartridge filter. According to them this ozone generator prevents biofilm on the filter thus reducing chlorine need. This sounds like bunk to me. They still recommend FC levels of 3-5ppm. They also talked about a UV sanitizer to remove chloramines. Now this I can get behind! My frustration lies in that when I told him I just want the UV system, not the ozone system, they insisted I need both! :blah: According to what I have read here I don't really need either! They told me I could purchase the paramount uv system at cost because it is new and they are wanting to get it into the market... For $675. The clear O3 system is $475 I believe.

What we really wanted was a salt system but EVERY contractor that we talked to discouraged salt, and would only install travertine coping and said this will still erode with salt. We wanted flagstone and moss rock so we gave up on salt. The Gunite shell looks amazing - MMG did an awesome job even with a hard downpour. My yard is now a mucky quagmire of mud/Gunite but the shell looks great!

Thanks for any help!!!!!

critrdoc

 

[jblizzle]

Welcome to TFP!

We would recommend neither if this is an outdoor residential pool. They are a waste of money as chlorine is all you need.

Use the search feature to find many discussions. Try "alternative sanitizers"

If you want to automate the chlorine, forget the tablets and look into a peristaltic pump or Liquidator for liquid chlorine ... since SWG sounds off the table.

Boggles my mind that you can not get what you want ... I would have kept looking for a different builder if they were so close minded.

 

[Critrdoc]

I know .... I am the paying client right? Thanks for the quick reply! I'm stuck with the builder now... So will just have to stick to my guns!!! I will request the peristaltic pump or liquidator. I will post pics soon!

 

[chem geek]

According to them this ozone generator prevents biofilm on the filter thus reducing chlorine need. This sounds like bunk to me. They still recommend FC levels of 3-5ppm. They also talked about a UV sanitizer to remove chloramines.

The bather load in residential pools is very low so biofilms in filters are very rare. That problem is more common in heavy bather-load commercial/public pools with sand filters. Chlorine alone kills bacteria in residential pools before they are able to form biofilms. This paper describes experiments using a high bather-load simulation at 1 bather per 350 gallons three times per day five days per week. By simply maintaining a chlorine level, bacterial concentrations on plaster coupons dropped from 1.26x10⁶ cfu/cm² to 3.7 cfu/cm². Yes, that's less than 4 bacteria per square centimeter. For the sand filter, the reduction was from 1.10x10⁹ cfu/g to 219 cfu/g. Chlorine should not be underestimated. Your bather load will be over 100 times lower than in this experiment.

As for UV and chloramines, the UV in sunlight in an outdoor residential pool not only helps to break down chloramines directly, but when it breaks down chlorine it produces powerful hydroxyl radicals that are strong oxidizers. Also, there are minimal chloramines created in low bather-load residential pools, especially those properly maintained with Cyanuric Acid (CYA).

There are over 56,000 members on this forum (and over half a million visitors during the peak summer who haven't joined) and biofilms have simply not been an issue in properly maintained pools (we have seen a handful of channeling and biofilms in sand filters from pools that didn't maintain chlorine levels prior to joining this forum). Chloramines have only been noticed when SLAMing a pool at high chlorine levels to get rid of algae or ammonia such as during opening a pool in the spring (if it was let go over the winter).

Why don't you tell your pool builder to just plumb in a straight section large enough to add ozone and UV in the future if you ever felt that you wanted to add it. That gives him a scintilla of hope while saving you money. You can promise to tell him the moment you find any channeling or biofilms in your filter and measure any significant chloramines in your TFTestkits TF-100 test kit (or Taylor K-2006) or notice any chloramine odor. He shouldn't wait up for your call.

 

[Isaac-1]

What they said, also when dealing with pool builders ask yourself one question, would you ask a car salesman advice on which options you should order on a car, and more importantly would you blindly take it? As has been mentioned above, it is simply not needed in a typical residential pool, at typical residential pool usage levels, so are you planning to have the softball team over to swim every day? Is your pool completely shaded from the sun AND you have a high bather load? If not you don't need any supplemental oxidation system, the sun is more than enough. As to the claim that these systems reduce your chlorine use, this is simply not true in a well balanced pool, in fact they increase your chlorine use, the key here is the term well balanced. Both UV and Ozone systems break down Chlorine therefore increasing its consumption in your pool, in a well balanced pool this leads to wasted Chlorine and higher use, in an out of balance pool where stuff is growing, then their claims may be true as the Ozone and UV may be helping to kill off those things faster than the Chlorine alone would do. It is our opinion here that if you have an out of balance pool, you should take the appropriate steps to correct it, not just steps that will temporarily mask the problem.

 

[Critrdoc]

Just spoke with the Salesman again, and he referred me to one of the Owners, who will call me back today. According to the salesman, the Ozone generator protects the plumbing and equipment from biofilm, and reduces your need for FC to 1.5ppm. This sounds dangerous. They build 80+ pools a year, and maintain hundreds, and they say this is how they build all their new pools and maintain them. I realize that there are large pool supply and equipment companies pushing these contractors to sell their products. I am just wondering HOW they get away with 1.5ppm FC. I mentioned CYA buildup with the Trichlor erosion feeder, and that I wanted a liquid chlorine peristaltic injector - like a Liquidator, and the salesman was now ready to refer me to one of the Owners. And the saga continues!

Critrdoc

 

[jblizzle]

Don't let them sweet talk ya .... what they are peddling is illogical.

 

[duraleigh]

The TFPC method does not involve any unnecessary products.....it's all about learning and understanding pool water chemistry.

Are they going to maintain your pool or are you? If it's them, then you will need to comply with their instructions. If it's you, then keep reading to understand better what we teach.

You are getting some bogus information from a place with an agenda. We don't have one.

 

[chem geek]

They still recommend FC levels of 3-5ppm.

According to the salesman, the Ozone generator protects the plumbing and equipment from biofilm, and reduces your need for FC to 1.5ppm.

So which is it? By "need" do they mean the level you need to maintain or the amount of FC loss per day?

Again, the FC level alone is completely meaningless in terms of chlorine's actual strength. They clearly have no understanding whatsover of the chlorine/CYA relationship. We have seen pools with ozonators using Trichlor pucks for chlorine get algae over time. Usually these ozone systems aren't strong enough in residential pools to leave any significant residual of ozone in the pool water so the only algae that gets killed is that which floats through the circulation system. Any algae stuck to walls grows very nicely if the chlorine level isn't high enough relative to the CYA level. You can have ozone systems powerful enough to leave a residual to prevent algae growth in the bulk pool water, but they are much more expensive than what they are selling and require much faster turnovers of the water than your pump is currently able to handle (and such fast turnovers are much higher in pump electricity costs).

They aren't really using the ozonator to prevent biofilms since the chlorine alone will prevent that. What they are doing is using the ozonator as a crutch to try and prevent algae growth when using Trichlor where for every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm. As the CYA level rises, the chlorine becomes less effective. As I mentioned, the ozone will help to kill free-floating algae, but will do nothing for algae that does not get circulated and is stuck or settled on pool surfaces.

In a properly managed outdoor residential pool, most of the loss of chlorine is from breakdown from the UV in sunlight. The amount used for bather load is negligible. Every person swimming in your 16,600 gallon pool for one hour would only use only 0.06 ppm FC. Even at 1.5 ppm FC with higher CYA levels (if that is what they meant) you'll lose from 0.2 to 0.7 ppm FC per day from the UV in sunlight. Also, ozone reacts with chlorine so increases chlorine demand, though in most residential pools the ozonator is so weak that this loss is not noticeable, but in spas it is noticed and roughly doubles the chlorine demand so one goes from a 25% daily loss to an over 50% daily loss. See Chemistries of Ozone for Municipal Pool and Spa Water Treatment for more technical info on ozone (see the section "Reactions of Ozone With Chlorine Species" in that paper).

If you use chlorine alone, you can figure you will use roughly 2 ppm FC per day if your pool is in full sun -- could be more or less depending on CYA level and may be less with more continual dosing from a peristaltic pump or The Liquidator. If you really wanted to use lower FC/CYA ratios, there are many ways of doing that, all of which have to supplement the killing of algae, but are all extra cost. However, with the minimum FC/CYA needed to kill algae being equivalent to only 0.07 ppm FC with no CYA, it doesn't make much sense to try and get it even lower.

Why don't you give them a challenge. If they want to put in the ozonator at no extra cost as a trial and have a way of turning it on and off, then you can try it out for a period of time and compare it on vs. off (say, a month at a time). Then, if after such trial period you decide to keep it, you pay for it. If not, then they can take it back. If they are so certain that the ozonator is going to be clearly beneficial, then their risk of loss is minimal (if they don't trust you for paying if you keep the ozonator, set up an escrow account). Or if they agree to refund your money if you pay them for an ozonator and are not satisfied (and you trust them), then you can do that instead.

 

[Critrdoc]

Thanks Chem Geek - I like your idea. Is it possible to change from Trichlor to plain chlorine tablets in an erosion feeder? This will be a brand new Ptech pool, and the chemistry of the pool initially is very important. I have downloaded instructions from this site, and will keep a close eye on the chemicals for the first month. I actually like the liquidator better, but find I get push back from anything other than their process. I have been reading - and re-reading your pool school and feel confident that I will be able to manage the pool just fine. Havn't heard from the PB yet today, but have all my information and evidence - thanks to TFP - ready to discuss the different merits of what they propose.

Thanks again!
Critrdoc

 

[jblizzle]

There is no such thing as "plain chlorine tablets" ... if you invent them you will be rich ... and likely breaking the laws of chemistry

 

[Critrdoc]

The correct question is are there chlorine tablets that do not contain CYA that can be used in an erosion feeder? Sodium hypochlorite, or some other salt without the CYA? In other words, once I have my CYA levels where I want them, can I substitute a different type of tablet in the erosion feeder, and only add Trichlor when indicated by testing - to keep my CYA from building up too high?

 

[jblizzle]

Short answer is no.
The solid forms of chlorine either have CYA (trichlor and dichlor) or calcium (cal-hypo) or lithium (very expensive and not tablets).
There are cal-hypo tablets, but generally are not recommended for pool as they dissolve too fast.
Also, you should NEVER put cal-hypo and trichlor/dichlor in the same container or it will be explosive.

You ideally should add CYA separately to get a bank in the water to protect the FC. You can use trichlor to raise the CYA some, but once the level is set you have to switch to liquid chlorine or a SWG.

Note in addition to adding FC and CYA, the pucks are acidic, so you have to watch that the pH does not get too low.

 

[danacc]

Thanks Chem Geek - I like your idea. Is it possible to change from Trichlor to plain chlorine tablets in an erosion feeder? This will be a brand new Ptech pool, and the chemistry of the pool initially is very important.
...

As others have already noted, there is no way to change from Trichlor to another type of chlorine tablet that doesn't add CYA. Cal-hypo tablets are the only alternative, and you can't put them in a feeder made for Trichlor, even if you clean it really, really well to avoid an explosion. They will dissolve too quickly in a trichlor feeder.

However, you can do what me and many here do--just leave it empty after the start-up period. That way, the pool builder can do what they are used to for start-up, protecting your PebbleTec warranty. Once start-up is done, you can remove any remaining tablets so that the CYA doesn't continue to rise.

I use my Trichlor feeder about once a year when we go on vacation. The CYA build-up during that time is manageable. For the rest of the year, I use liquid chlorine (bleach). You may find the feeder useful in special circumstances. It doesn't hurt anything to just leave it empty.

 

[shuye]

I agree with danacc - let the PB do the startup as they wish to satisfy the warranty and then switch to liquid chlorine (Bleach). I followed this thread and set up my stenner system:

another-happy-peristaltic-pump-injector-t53128.html

Since you are in Cypress, there is a location near you that sells 10% chlorine in bulk based on this thread:

houston-wheres-the-bleach-t64430.html

It's too far for me - so I use the jugs from walmart, but its right next door for you.

Steve

 

[Critrdoc]

You guys are awesome ---- Thanks so much! I am still waiting to hear from the PB but I have a plan. I will let them do the startup & then convert to a liq bleach system. Great info on how to do just that. The stenner pump looks like something I can set up without too much trouble. What a real relief it is to have this forum. Y'all Rock!

Critrdoc