I been doing some " ozone kill chlorine " experiment

[SPP]

Hello Gang,

Its been a long time.

I was curious to test for myself if ozone will destroy chlorine or chloramines.
Now that the TP-100 test kit have arrived, I am learning how to use it.

I just got a Prozone PZ2-4V which is a 2 gram per hour model. I already installed it on my pool plumbing, the one with Hayward 2Hp pump.

So when the test kit arrived, I am dying to test both the TF-100 and the ozone system.
Anyhow, I happened to be able to borrow my friend's ozone system and it is the same 2gram/hour output as mine and comes with air compressor, because his pump room is like 6 feet under his pool.

I use approx 25 gallon ( 95 liters ) Rubbermaid cooler box as water container.
Thanks to the TP-100, I can now finally detect combined chlorine level. I suspect its not normal as I am getting a mild smell of "chlorine" from the water, even though Total Chorine was way above 3PPM ( that's all my simple Pentair test kit can do ).
Water is very clear.

I am in the process of shocking the pool when the test kit arrived and what a blessing.
So I rigged the borrowed ozone

Anyhow these are the numbers :
9 Aug 2008
Water about 25 gallons or 95 liters
Time :18:05
FC = 5.5 CC= 1
I run the ozone system and since I do not use the supplied venturi injector and I don't want to use my 1.5HP Pentair pump on trolley on such a small water container, I decided the ozone system with compressor can inject ozone if I can make small enough bubbles. So I went to the aquarium shop and got 2 of sand stone aerator block and a wooden aerator block. I did not know they have a wood one ...which in fact produces very fine bubbles.[attachment=2:1x31n4rc]Ozone generator and compressor.jpg[/attachment:1x31n4rc]

 

[SPP]

Gee...how come the photo does not stay in the order as I upload them ??

Anyhow the I keep the ozone generator running for 28 minutes.
Then I test the water immediately. The ozone smell was strong...smell like they said...a photocopy machine in action.

You will be suprised at the numbers. I been trying to surf if DPD powder reading ( color in this case ) will show error if ozone is in the water, since ozone is also an oxidizer. At 25*C the ozone half llife is 12 minutes, my water temp was 28*C...I suppose there are still dissolved ozone in the water.

The numbers are :
FC = 7.5 CC = 1 Time 18:32

The numbers can't be right...??? How come I am getting more FC now ?

So I decided to test once again. And this time I will allow 15 minutes wait before testing the water.

Start ozone generator at 19:35, stop at 20:05 and wait 15 minutes.
The numbers are :
FC = 7 CC = 1 dang, still confusing


So I tested again, run ozone from 20:30 to 21:30 with 30 minutes wait before reading.
The numbers are so crazy, I must have done something wrong, but I know I did not test wrong.
FC = 1 CC = 4


Still not happy, I tested again. From 00:10 to 01:15 with 25 minutes wait before reading..there goes my Saturday nite.
FC = 4.5 CC = 0.5

This morning I let the water be in where the sunlight will hit it hard at mid day..only a few hours and I will test it again.
My pool is shaded and I do not get too much direct sunlight.

OOppss, I almost forgot My CYA was 25 ( I am quite uncertain here )...sorry I am still learning how to see that black dot on the bottom of the test tube.
The PH was 7.8..yep a bit too high.

I must devise a more reliable method.
The FC going up and down like that and to the point I had CC = 4 is crazy.

Any test method suggestions welcome...pleasezzzz.

Thanks
SPP

 

[Guest]

You will be suprised at the numbers. I been trying to surf if DPD powder reading ( color in this case ) will show error if ozone is in the water, since ozone is also an oxidizer.

Yes, it will. DPD is often used as a test for Ozone.

 

[SPP]

Thanks water bear. i will use thiosulfate to remove the chlorine first. Let see what the TP-100 DPD will show for ozone.

 

[Guest]

Thanks water bear. i will use thiosulfate to remove the chlorine first. Let see what the TP-100 DPD will show for ozone.

Thiosulfate is a reducing agent and will also probably effect ozone levels in the water. Thiosulfate is not specific for chlorine but will effect any oxidizer.

 

[Guest]

I see an error in the way your experiment is set up. What you need is two identical set ups but only one with ozone. Monitor the chlorine levels in both and see if the chlorine in the ozone setup depletes faster. Realize that you will see an increase in the reading in the ozone tank while there is ozone in the water so I would test both tanks on a regular basis, say every 15 minutes or so for a period of several hours and repeat the experiment several times to see if the results are statistically significant.

I think you will find if you plot both tanks DPD readings you will see a rise after ozone in the ozone tank and then it will drop farther than the non ozone tank after a period of time. You also will need to vary the amount of ozone used so you are sure you are using enough to show up by your testing method.

 

[SPP]

Roger that, on the thiosulfate. I was surfing and read your post in pool&spa forum and you reccomended thio to first remove chlorine for ozone testing. My aquarium friends also reccomended thio for chlorine removal.

Your advised test method for two seperate containers sounds very good. Will do that for next test. Thank u.

I think I will also use zero chlorine water and ozonate it, and see what reading do I get on the FAS/DPD, for curiosity sake....he he he...

 

[Guest]

Roger that, on the thiosulfate. I was surfing and read your post in pool&spa forum and you reccomended thio to first remove chlorine for ozone testing. My aquarium friends also reccomended thio for chlorine removal.
The post I made on poospaforum was in regard to testing ozone with DPD, not FAS-DPD. I also spoke of other, more dependable methods of testing for ozone.
Your advised test method for two seperate containers sounds very good. Will do that for next test. Thank u.

I think I will also use zero chlorine water and ozonate it, and see what reading do I get on the FAS/DPD, for curiosity sake....he he he...

A good idea. However, you might want to get an actual ozone test kit that uses the indigo method of testing. It is more depenable than DPD testing since it is more specific.

 

[SPP]

Dang...FAS/DPD..& DPD i thought the same product...

I will try to source the type of ozone test kit you mentioned...thanks.
There are so many types on the market...I don't know what to do actually.

What confuses on the ozone is manufacturer claiming 2 gram per hour.
2 gram per hour based on a fix/reference air flow or "no matter how fast" the airflow and all i will ever get will be only 2 grams per hour ?

thanks Bear

 

[Guest]

thanks Bear

FYI, a waterbear is not a bear but a microscopic animal also known as a tardigrade.

 

[SPP]

 

[SPP]

Hello Waterbear,

I just did another test.
I use my city water and test it first.
With OTO, i get zero TC
With FAS/DPD from TP-100, I get Zero FC and there is a very-very-very slight hint of CC. I don't know if my city water authority is using chloramine as disinfectant...no idea.
PH was abit over 7.2 but lower than 7.6.
Water in bucket about 4 gallons only.

I then run the ozone generator for 95 minutes. I can't control the output, it does not have adjustment feature.
I tested with OTO, no reading.
I tested with FAS/DPD, i get zero FC but for CC I got slightly above 0.5PPM...wow, that's odd ???

I don't want to speculate on anything but if for some reason the ozone residual seems to be read as CC in FAS/DPD, that could be the reason I am now in the middle of a confusing pool SHOCKING session.

I installed the 2 gram ozone generator since Wednesday and been running it for 24/day non stop for fun.

When the TP-100 kit came I got to play with it on 8 Aug. My pool boy reported that my CL level has been high above 3 PPM ( my Pentair test kit only reads to 3PPM ) for the past few days.

Between July 6th to July 16th there were 4 divers everyday in the pool, according to my "pool loading log book". They spent like 4 hours per person in full dive gear. I don't have the "sanitation log book" of that period on hand now.
However I do recall one day when the water was mildly cloudy on 27th July after a dive session with 4 divers.
My reference to mildy cloudy is the 3" depth numbers in red sticker I stick on the end of the pool wall, if I can't see it from the opposite end or +-35 feet away in decent daylight and can only see if from 20 feet, then my pool is not at peak clarity. Very cloudy is when I can't see the tiles grout properly at the 13 feet max depth. At maximum clarity I could see those numbers in its original red colour end of pool to end of pool. A few days later after being assisted with the back up trolley pump, water was clear again. I think some of the divers did not take a proper bath before the dive training and must have been sweating a great deal. So my pool have been mild cloudy "burning" their personal garbage...I hope they did not pee in there... .

I been keeping TC at 3PPM for the past few months since diver load in the pool have increased. This is also because of the advice from you all nice experts at TFP.... ...thank you.

I look at the sanitation log book that started 14th July and it was : ( TC reading only and before bleach added )
29 July TC = 2+ PPM 1 liter bleach 12% was added at 18:45 pm
30 July TC = 3+ PPM 2 liter bleach 12% was added at , I notice it was done because of 4 divers in the pool.
31 July TC = 3+ PPM no action
1 Aug TC = 3 PPM no action
2 Aug TC = 3 PPM no action
3 Aug TC = 2 PPM 2 liter bleach added 09:35AM
4 Aug TC = 3+ PPM no action
5 Aug TC = 3PPM 1 liter bleach 12% added 16:50 PM
6 Aug TC = 3+ PPM no action
7 Aug TC = 3+ PPM no action OZONE SYSTEM ACTIVATED EARLY MORNING

8 Aug TC = 3+ PPM no action OZONE SYSTEM RUNNING NON STOP
Use FAS/DPD first time. FC = 8.5 PPM did not test CC
I can smell very mild smell of "chlorine" in my pool if I put my nose very close to pool water. Water is very clear but this is a good time to play with the pool because of the TP-100 kit.

9 Aug FC = 6 PPM CC = 1.5 PPM tested at 06:45 AM OZONE SYSTEM RUNNING NON STOP

9 Aug transfer 25 gallons to Rubbermaid cooler box for experiment with ozone, if ozone kills chlorine
Water numbers in cooler box. Water about 25 gallons or 95 liters
Time :18:05 PM
FC = 5.5 CC= 1

10 Aug Pool numbers. FC = 6.5 CC = 1 CYA = 25 at 07:15 AM
10 Aug Pool numbers. FC = 6 CC = 1 PH 7.6 to 7.8 at 18:15

10 Aug Lower pool PH, add 2 liters HCL 30% at 18:15
Pump on trolley activated to speed up circulation. With main pump and back up trolley running, 1 pool turnover estimated at 5 hours. Main pump measured at 12 hours per turnover. Trollley pump estimated at 8 hours per turnover.
OZONE SYSTEM still runnning.

11 Aug Lower pool PH, add 1 liter HCL at 00:030 AM, by 06:30 AM PH down to 7.2
Shock the pool with 6 liters 12% bleach at 06:30AM to achieve 11 PPM
Open up 25% of the sunshade to maximize sunlight. Too bad can't open all.
Pump on Trolley still running to assist circulation.
10:00 AM Test water in deep end position, FC = 5PPM, TC = 0....weird !!!!
10:02 AM Test water at shallow end position, FC = 10.5 PPM , CC = 0
10:04 AM Test water at shallow/Deep point, FC = 11.5, CC = 0
01:50 PM Test water at deep end ( my pool boy ), FC = 8, CC = 1.5 ...Hello ????? What's happening ??
7:15 PM Test water at deep end, FC = 9.5 , TC = 0.5
7:17 PM Test water at shallow/deep point, FC = 10.5 , CC = 0.5 PH 7.2 to 7.4
11:00PM Test water deep end but opposite side, FC = 9.5 , CC = 0.5 ( but very very mild red )
11: 25PM I am now confused, so I decided to turn off the ozonator, because my test with tap water seems that ozone will trigger increased CC for the FAS/DPD. I added another 4 liter of bleach 12% to hit 13 PPM.
By 11:59 PM, I have circulated estimated 6.4 times pool water starting at 18:15 PM on 10 Aug.

12 Aug 01:00 AM ( I am 12 hours ahead of USA east coast )
FC = 11.5 , CC = 1 and the last 0.5 is very very mild red.

The ozone in water should dissapear by tomorrow. I hope to get that zero CC again. If the CC gets zero and I am still getting chlorine mild smell if my nose touch water, I will use thiosulfate to lower chlorine and slowly use my nose to see at what FC ppm I can smell chlorine. :blah:

Fun test but confusing....
I learnt that some US states uses Chloramine in their city water...WOW, what will happen to pool owners ?

SPP

 

[SPP]

Finally, I get the CC to ZERO !!!!!!

The ozonator has stop running since 11:25PM 11th Aug.
FC & CC 1st test 09:30AM and I did 2nd test at 11:30AM today 13th Aug, so ozone been off for 34 hours & 5 minutes.
I stopped my Hayward pump ( 12 hours per turnover ) since 11:00 AM 12th Aug, regenerated the Zeolite, turn on the pump only at 10:00 AM today 13th Aug.

I have not regenerate my Zeolite for a long time, and its ammonia catching capabilities I think is already over loaded.
I hope to be able to reduce any CC that may be re-introducedand and can proceed with testing the ozone once more.

I am still curious why my city water shows increased CC after being ozonated for 95 minutes, If the FAS/DPD reads dissolved ozone as CC, I will test further as followed.

Will do this about 24 hours after my Zeolite starts filtering.
Test all water for CC. I will take a pail of water of the pool before I turn on the ozonator, keep it under the shade and cover it well. Turn on my permanently plumbed ozonator for an hour and catch some water coming out of the return nozzle and test for CC on this batch of water and the one in the pail. I will make sure no one use the pool.

I will update.

 

[Guest]

Ozone will test as CC with the FAS-DPD test, as will any oxidizer like MPS, hydrogen peroxide, or sodium percarbonate. (The last two also destroy chlorine in a similar way to ozone.)

 

[SPP]

Oh oh...I am in trouble....oh oh

How then do I test my chloramine CC with ozone generator running ? Unless I turn off the ozonator for at least 24 hours yah ? Holy Cow !!!!

Chief, thank u so much. What would I do without you.