Testimony to Ozone Generator Handling CC

[The Cabana Boy]

Pool has been open since April 4. I've just been maintaining since then with no swimmers due to water temps running 65 - 70 degs. All the numbers have been good except the cya is sitting at 80 or 90. It was off the charts when I opened, probably around 140, but has been coming down with the frequent rains.

I've been running the pump 10 hous per day with the ozone generator set at approximately 25%. I skipped testing on Wednesday but found the FC at .4 and CC at 1.8 at noon on Thursday. I try to maintain FC at .5 to 1 so I added a pint of 8.25% bleach and turned the ozone generator up to about 75%. When I tested at 6:00 pm, FC was at 2 (I over shot a little) and CC was down to .2. Tested first thing this morning and CC is now at 0.

I've had some skepticism of the claims made by the pool builder concerning the ozone generator. I'm only 10 months into this new pool, but very pleased that the ozone generator came through and diverted a slam.

 

[jblizzle]

Having low CC is all well and good, but your pool is not sanitary or safe for use because your sanitizer (FC) level is too low for your CYA level.

I would never swim in that pool.

TFP stands by the claim that ozone / UV are a not-needed added expense that add no value to a private outdoor residential pool.

 

[Richard320]

That does not compute. According to poolmath, 16 oz of 8.25% bleach in a 12,500 gallon pool will only add .8 FC.

.2 + .8 ≠ 2.0+ There has to be some other source of Chlorine. Is that feeder listed in your signature still adding FC and CYA?

Ozone will oxidize organics, so that part is not surprising. However .5 FC with 90 CYA is not sanitary. With no one swimming, it's no big deal, but it will be later on in the season. There is no residual ozone in the pool itself. It only kills viruses and bacteria inside the chamber, not in the pool. I wouldn't rely on Ozone to keep the pool safe to swim in. http://www.troublefreepool.com/thre...s-and-quot-chemical-free-quot-pools-The-Truth!

 

[Donldson]

I am not entirely sure what you are testifying here. I have let my pool get to zero FC before and had zero CC and no algae during the fall before, but that doesn't mean it "worked". It means I got lucky.

It is your pool, run it as you please, but I don't see anything in your post that backs up the claim that the ozone made any significant contribution.

From my HTC One via Tapatalk

 

[The Cabana Boy]

That does not compute. According to poolmath, 16 oz of 8.25% bleach in a 12,500 gallon pool will only add .8 FC.

.2 + .8 ≠ 2.0+ There has to be some other source of Chlorine. Is that feeder listed in your signature still adding FC and CYA?

Ozone will oxidize organics, so that part is not surprising. However .5 FC with 90 CYA is not sanitary. With no one swimming, it's no big deal, but it will be later on in the season. There is no residual ozone in the pool itself. It only kills viruses and bacteria inside the chamber, not in the pool. I wouldn't rely on Ozone to keep the pool safe to swim in. http://www.troublefreepool.com/thre...s-and-quot-chemical-free-quot-pools-The-Truth!

My intent was to add 16 oz but I didn't measure and think I over estimated my pour. I have the feeder turned off and just use bleach to maintain residual FC. I will probably have to do a partial drain and refill to get my cya down but I'm utilizing spring rain and drain until the water temp gets warm enough for swimming.

It's my understanding that even minimal amounts of chlorine will kill most bacteria but cannot ward off algae blooms -- and thats where the ozone steps in. Either way, I see ozone systems are controversial and I have no desire to argue either side. I am already vested in one and the point of my post was simply to relay my experience. I guess time will tell (of course I spent my childhood swimming in cow ponds and still spend many summer weekends at the lake, so swimming in a crystal clear pool is bonus).

 

[The Cabana Boy]

I am not entirely sure what you are testifying here. I have let my pool get to zero FC before and had zero CC and no algae during the fall before, but that doesn't mean it "worked". It means I got lucky.

It is your pool, run it as you please, but I don't see anything in your post that backs up the claim that the ozone made any significant contribution.

From my HTC One via Tapatalk

I'm not entirely sure comparing zero FC and zero CC to a CC of 1.8 is the same thing. Maybe it was just luck, coincidence, or an act of God, but my CC went from 1.8 to .2 in six hours and I'm glad I didn't need to slam the pool to get it there.

 

[Patrick_B]

When Cya is in the water, minimal amounts of free Chorine will not perform at the minimal residuals you are likely talking about. Once Cya is involved, those effective residuals have to increase, and must be in proper ratio to your Cya level.

 

[jblizzle]

The sun burns off the CC ... so that could also explain the drop.

Having a high CC is only 1 of many possible signs of a problem in your water.

Perhaps you should take a look at This Chart which shows the active levels of chlorine as a function of CYA as Patrick was talking about. If you had 0 CYA, then a FC of 0.1 would be just fine with an "active" level of 0.05 ... But with a CYA of 70ppm (lower than yours), then you must have a FC of about 8ppm to have the same sanitizing effect.

 

[The Cabana Boy]

The sun burns off the CC ... so that could also explain the drop.

Having a high CC is only 1 of many possible signs of a problem in your water.

We have been completely overcast for two days although I don't know if the clouds eliminate all sun burn off.

I just got my K2006 kit earlier this year so this is the first year I've been able to accurately measure CC. Even though CC is only one of several possible signs of a problem, is it correct that CC >.5 indicates something is growing and requires immediate attention? I fretted about the elevated CC but don't know if I over reacted.

 

[jblizzle]

No, a high CC does not necessarily mean that something is "growing". You can have a pool full of algae and 0 CC. And with your low FC, you can have a pool full of viruses / bacteria with no algae and no CC.

 

[JasonLion]

Technically, CC at 0.3 or higher is a problem. Most people do the CC test in steps of 0.5 however, so we count a level of 0.5 (when done in steps of 0.5) as being below 0.3 (which it almost always is). You were doing the test in steps of 0.2, so anything over 0.2 is a problem.

 

[The Cabana Boy]

Technically, CC at 0.3 or higher is a problem. Most people do the CC test in steps of 0.5 however, so we count a level of 0.5 (when done in steps of 0.5) as being below 0.3 (which it almost always is). You were doing the test in steps of 0.2, so anything over 0.2 is a problem.

Thanks, makes sense. I had read on other sites that .3 was the threshold but thought TFP was just giving more leeway.