Ozone Joes??

[dmanb2b]

Chlorine in outdoor residential pools is mainly consumed by UV, not contaminents or bacteria. How does ozone reduce my chlorine usage attributed to this fact, in an outdoor pool?

I think the idea is that the chlorine we put in our pools, thinking the BBB troublefree way, performs two functions. Sanitation & oxidation. Ozone is purely an oxidizer, so it "relieves" the chlorine of the oxidation function.

However, the BBB gurus have noted in another thread that you can't tell the chlorine not to oxidize CCs & it has no idea if there is an ozone generator at the equipment pad. They have also formulated only a small amount of the chlorine you put in your pool is to provide the oxidation function.

But I've seen guys with numbers like FC: 0.5, CC: 1.5 an ozonator could make that FC: 0.5, CC: 0.0 If FC: 0.5 is enough to sanitize a pool, then the pool is still safe. I know CYA makes it impossible to sanitize a pool with 0.5ppm of FC... but what if all you need to sanitize your pool is 4ppm at your CYA level, but the suggested number is 6ppm or 7ppm to provide enough chlorine to oxidize the CCS.

If the ozonator can take the place of the extra 2 or 3ppm for oxidation & you only have to maintain the 4ppm, would that be of any benefit?

At the same time, once you get your FC to the desired level... 7ppm you are pretty much only maintaining the 2 or 3ppm your pool uses daily..... so it's probably the same thing.

My point is that if sunlight/UV eats up 2ppm of FC per day, ozone is NOT going to reduce that chlorine demand, in fact it may increase your chlorine demand as noted by Richard.

My pool is used by 4kids and 2 adults, almost every day for 4 months straight. In 3 years of ownership, following BBB (I test my water daily), I have never had to shock the pool, nor has my CC ever registered above 0.5ppm. Most folks seem to think my saltwater pool is not a chlorine pool (wrong), as they state the water does not smell. I need an ozone generator why?

Listen, I understand you may have invested in one, and having it as a saftey net can do no harm, but if you maintain your pool regulary, it's just not a necessity to have a sanitary, clean, soft feeling pool.

 

[thunderkyss]

Listen, I understand you may have invested in one, and having it as a saftey net can do no harm, but if you maintain your pool regulary, it's just not a necessity to have a sanitary, clean, soft feeling pool.

I was just thinking out loud in the post you quoted. I don't know what the answer is & don't pretend to. I do have one on my pool & I plan to experiment when I get this BBB thing down to a routine.

But I also have a raised spa on the pool, the ozonator may be required for all I know. I also have a family where I can expect 13+ people in my pool on a regular basis ranging from 3 years old to 50 so the ozonator may be of more use on my pool than yours....... I'll keep you posted.

 

[JasonLion]

If the ozonator can take the place of the extra 2 or 3ppm for oxidation & you only have to maintain the 4ppm, would that be of any benefit?

In a typical residential pool, 95+% of the chlorine is going to maintain a suitable sanitizing level, hardly anything is used up oxidizing. Thus, there is hardly anything for the ozone to improve on.

Sure, there will be a few moments in the life of any pool where ozone might help, the last hour or two of a big pool party, that one really bad algae attack that resulted in a high CC level, but those moments are few and far between and can handled with chlorine alone without any major problems. You end up spending the money just to save a minor annoyance five or ten times in the life of the pool.

One of the important principals we teach here is keeping things simple. Don't spend money you don't need to spend or add complexity that you don't need to add. Pools are already complicated enough, why add another piece of equipment that doesn't do very much?

 

[thunderkyss]

One of the important principals we teach here is keeping things simple. Don't spend money you don't need to spend or add complexity that you don't need to add. Pools are already complicated enough, why add another piece of equipment that doesn't do very much?

Sorry, I was just playing devil's advocate.

 

[chem geek]

If FC: 0.5 is enough to sanitize a pool, then the pool is still safe. I know CYA makes it impossible to sanitize a pool with 0.5ppm of FC... but what if all you need to sanitize your pool is 4ppm at your CYA level, but the suggested number is 6ppm or 7ppm to provide enough chlorine to oxidize the CCS.

The recommended FC levels relative to the CYA level have nothing to do with the amount needed for oxidation. The amount needed to oxidize bather waste in most residential pools is very low. Again, the bulk of chlorine demand is loss from sunlight.

The reason for the FC levels relative to CYA in the Chlorine/CYA chart is to have enough active chlorine to prevent algae growth. Ozone does nothing to inhibit algae growth on pool surfaces. So if you really wanted to lower your active chlorine level, then you need a supplemental bulk water algaecide or equivalent at extra cost, but most have side effects or are only partially effective (Polyquat or linear quat algaecides, copper ions, borates, phosphate removers, etc.).

Again, ozone isn't the answer if you want a lower active chlorine level. The only answer to that is something in the bulk pool water that prevents algae growth, period. And again, any ozonator sized large enough to actually do anything in most residential pools that typically have low bather loads will actually consume more chlorine by oxidizing it to chloride or chlorate than it saves. This is why ozonators are most useful in high bather-load situations such as commercial/public pools (since there are so many bathers in the pool most of the day) and in residential spas (since the water volume is so low) used every day or two.

So yes, if you truly have 13 people in your pool on a regular basis, meaning every day or two, then an ozonator could be helpful. If this only occurs infrequently, then the ozonator you get should be able to be dialed down or turned off for the long stretches where it will consume more chlorine than it would save. You would only turn it on or up to a higher output when you expected the higher bather load. In that case, it should reduce the amount of extra chlorine that would have otherwise been needed.

 

[learthur]

Having both a SWG and an ozone generator I can give the practical points:

1. Ozone manufacturers mislead consumers by saying you will reduce chemical use by (50-90%). Sure you can do the low chlorine thing, but you will have algae as referenced above.

2. My ozone has provided a small benefit in earlier recovery after high bather load....especially in spa use, and somewhat reducing chloramines. Don't think an ozonator will reduce your chloramines to zero for ever and keep them there. It won't. It is not THAT effective....but it will help. Most of my chloramines presumably come from the heavy leaf load I have with lots of trees.

3. Ozone will oxidize metals. I get iron from leaves and acorns and it gets oxidized and stains my plaster over time. This is treated with AA.

4. All residential ozonators are only minimally effective when installed as typically instructed using a venturi injector. This means that as stated earlier, without a contact tank and contact time, you are loosing most of the benefit from your ozone unit.

5. Ozone is a chemical too! It is a noxious, highly oxidative, very potent gas that irritates human respiratory tract and is linked to asthma in children if exposed. That is why residential ozone units are very low ozone producing devices. This is why large commercial ozone units require contact tanks and off-gassing scrubbers and ozone air quality monitors if used indoors. It is not necessarily any safer than chlorine.