Clarification on Ozone vs. UV---High daily FC loss

Krysib

Well-known member
Jun 18, 2020
84
League city TX
Hi All-

Thanks so far for all of your help! We have a brand new pool, and unfortunately I didn't find this site until mid-way through our build. Builder 'package' included UV and Ozone combo system, which has been turned on per builder settings since fill. I've been working on the start up chemicals and dialing in the process per TFP methods as I learn them.

However, this week I have had to put in a gallon of 10% bleach per day in order to maintain chlorine. CYA is at 60 due to the August TX heat and trying to maintain on the high side of recommended so I don't go too low (8-9PPM) (Getting pretty expensive and hubs wants to go back to the pucks the PB left).

After educating myself a bit more it seems it may be the UV or ozone system.

I performed an OCLT last night and got 1.5ppm loss. I am assuming since its a new pool that we don't have any organics yet (but I may be way off here...)

So that led me to the UV/Ozone research. From my research on the Paramount Ultra UV2 system, while it may not be helping and consuming additional electricity, it should NOT be consuming FC as it's primary wavelength does not break down FC like the Sun's wavelengths.

Which leaves the Ozone system. The PB has this connected directly to the pump, so I believe it has been running nonstop since day 1.

After my OCLT last night, and subsequent to my additional TFP research, I went outside to figure out how to turn off the UV/O3 systems. The UV system automatically turns on based on flow rate, so when the pump is at 30% or higher. I turned my pump down to 25% today (PB had it set at 65% for 12hrs during the day). That should take care of the UV. For the ozone, I don't see anyway to turn it "off", but it did have a flow valve that I closed down completely.

In the time I took my morning OCLT at 7am until I had decided to turn off the UV/O3 systems at 9:30am, I had lost 1.5PPM FC (0.6PPM per hour). I have been loosing 7-8PPM FC per day, so at 0.6PPM for 12 hours=7.2.

I'm going to test again tonight, might even do an afternoon test here soon to sooth my curiosity.

In the meantime, is my understanding correct that it is probably not the UV system but instead the OZONE system that is causing the huge daily FC loss?

I think I can live with turning the OZONE flow regulator off, but I'm not sure how I would turn off the UV system. It appears that the PB connect the wiring for the Pump/ozone/uv together as I do not see a master breaker labeled for the individual components.

Find my logs here:
 
That is a big FC loss daily and overnight. I think you are heading down the correct path of trying to turn it off and do another OCLT to see if that is the culprit.

I did look at your logs (which are probably the most detailed logs I've ever seen, nice job). You do have several tests under the Minimum FC of 5 within the last week, so I'm not sure you can rule out algae.
 
When ozone doesn't have any contaminates to slay, it slays what is there- FC! So yeah, it will increase FC loss.
Whether that can account for *all* your loss is another issue.

Can you take a pic or two of your equipment pad and the wall hung devices?- maybe someone here can suggest a fix for how to d/c the ozone.

Do consider running an OCLT- rule out that your occasional basement level FC readings didn't allow algae to move in.
Overnight Chlorine Loss Test

Was a salt water chlorine generator ever discussed?

Maddie
 
I assume the UV/Ozone does not run without the pump running. I would try re-testing tonight, turn it all off right before you test and turn it back on right before your morning test. That should definitely tell you if your FC is eating up anything.
 
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That is a big FC loss daily and overnight. I think you are heading down the correct path of trying to turn it off and do another OCLT to see if that is the culprit.

I did look at your logs (which are probably the most detailed logs I've ever seen, nice job). You do have several tests under the Minimum FC of 5 within the last week, so I'm not sure you can rule out algae.


Thanks JJ_Tex!!!---I'm trying to get a handle on all this pool chemistry so the more detailed the logs the better! I do wish I would have retested the FC after my gallon addition every day to ensure potency of the CL, but I did last night and saw the expected increase and dates on the bleach are 'fresh'.

My CL tests since taking over the pool have been all over the place, but I dose every night and try to dose high (9PPM) so that it doesn't fall too low.

Sorry I can probably research/google the forum for this as well, but besides the OCLT, what other indicators of algae should I be looking for? My pool water is crystal clear, and I see no buildup or residues anywhere.

Edited to add-the UV for sure doesn't run when the pump is on, and given the ozone is piped into the pump that is a good assumption. I can just turn off all of the equipment for tonights run. I also hope to see some decrease in FC consuption today with turning them down/off.
 
When ozone doesn't have any contaminates to slay, it slays what is there- FC! So yeah, it will increase FC loss.
Whether that can account for *all* your loss is another issue.

Can you take a pic or two of your equipment pad and the wall hung devices?- maybe someone here can suggest a fix for how to d/c the ozone.

Do consider running an OCLT- rule out that your occasional basement level FC readings didn't allow algae to move in.
Overnight Chlorine Loss Test

Was a salt water chlorine generator ever discussed?

Maddie


Hi Maddie-Thanks!! I did run the OCLT, see results in my OP. I will try to run tonight with the equipment off per suggestion.

As for the SWG, I had asked every PB I interviewed about it and they all were against it. Had I found this forum a month earlier I would have asked to trade out the UV/ozone for SWG!!! Oh well, first pool and I've learned (and I'm sure will continue to learn!).

I'll take a pic and post when I go down to take another FC reading. Although not "official", if I'm seeing less than 0.6PPM FC loss per hour since my 9am test, I think I'm on the right track.

Just hoping its not an algae bloom already!!!!
 
Hey Krys and Welcome !! Don’t feel too bad about the builder package. Many times removing certain parts of it does not get you a fair discount accordingly. If people get anything off it’s usually minimal. They love selling that stuff in Texas and we see it daily. Check these links out for a more detailed description of what you have. There are plenty of good folks here to guide you until the ABCs of Pool Water Chemistry click.
 
Hey Krys and Welcome !! Don’t feel too bad about the builder package. Many times removing certain parts of it does not get you a fair discount accordingly. If people get anything off it’s usually minimal. They love selling that stuff in Texas and we see it daily. Check these links out for a more detailed description of what you have. There are plenty of good folks here to guide you until the ABCs of Pool Water Chemistry click.

Thanks NewDude! I had seen the UV link but missed the ozone one for some reason!

And I agree-I don't think I wouldn't have gotten the value out of removing it given it was their 'package'.....live and learn!
 
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OK-Bad news.....or maybe just not conclusive news.....

I just ran down to take a few pictures of the equipment pad, pool and retest. Given that I had turned off UV/O3(or tried to) I had thought I might see a less than 0.6PPM FC loss per hour.

My latest test showed 3ppm CL, which is a 0.9PPM/hour Cl loss. So maybe an organic after all. I will do an OCLT again tonight with the pump off and see where that gets me.

In the meantime, here is my pool, equipment pad, where the Ozone connects into pump and also a picture of where the PB told me I could put a SWG in the future (although he reiterated they typically build with Chlorinators).
 

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Lets make this easier on you and save you some reagents-
Use a 10 mL sample size, then each drop will equal 0.5 (i.e. total number of drops divided by 2 equal your FC or CC value).

(sidenote- ever go to Kelley's at the exit to La Marque for the Chicken Fried Steak? Delicious!!!!)
 

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The picture of your pool it looks really cloudy. Is that a photo issue? Can you clearly see the main drains?
 
Lets make this easier on you and save you some reagents-
Use a 10 mL sample size, then each drop will equal 0.5 (i.e. total number of drops divided by 2 equal your FC or CC value).

(sidenote- ever go to Kelley's at the exit to La Marque for the Chicken Fried Steak? Delicious!!!!)

Hi Yippee Skippy! Thanks, I am using the 10mL sample size-otherwise I think I would have run out of reagent by now as much as I've been obsessing!!!! (the oddball number was from the math of making a per hour CL loss calculation 7.5-3=4.5PPM FC lost in 5 hours. 4/5=0.9PPM lost each hour)

And NO!! Not that location of Kelley's! I have tried others, but its been years! Hubs is looking at a new job in La Marque so I'll have to tell him about it!
 
Beautiful pool !! Sweet decisions made in the planning !!

I’m with Marty above, the water looks off. We can help with that and your OCLT will be the 1st step.

it looks to be plenty of room for a SWG if the time comes. Always nice to have options.
 
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Beautiful pool !! Sweet decisions made in the planning !!

I’m with Marty above, the water looks off. We can help with that and your OCLT will be the 1st step.

it looks to be plenty of room for a SWG if the time comes. Always nice to have options.

Thanks Newdude! We think we did pretty well with the planning considering neither of us have ever owned a pool! And while we did look into SWG, we were steered away from them as a "fad" that had gone out of style. Oh well---good to hear we have plenty of room to add it! I've got some amazon rewards dollars burning a hole in my pocket and they sell the hayward SWG!! destiny!

Bad news on the cloudiness, I'll turn the pump off tonight per your suggestion and go from there. I think our pool is so much clearer than any of those in my neighborhood--but I'm probably biased.


The picture of your pool it looks really cloudy. Is that a photo issue? Can you clearly see the main drains?

Went down to take pics of the deep end drains specifically. Still pretty turbulent on the top due to the wind picking up, but I can see the main drain, easily. (I took one of the spa too because the wind isn't stirring it up on the surface as much yet)
 

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You have an integrated spa. Do you not have any form of automation system to control it? Nor a heater?
 
I think our pool is so much clearer than any of those in my neighborhood--but I'm probably biased.
You are biased and it’s not a bad thing. Once you learn the ropes and see the results you will understand how messed up everybody else’s water is. Having the clearest water on the block doesn’t always mean much depending on the block. Check this out if you want to be blown away.
 
You are biased and it’s not a bad thing. Once you learn the ropes and see the results you will understand how messed up everybody else’s water is. Having the clearest water on the block doesn’t always mean much depending on the block. Check this out if you want to be blown away.


So with the new pics-turbulence and all you think mine still looks cloudy?

Those are some WOW pics on that thread. Pool parties I've been to in the 'hood can't shake a stick at those crystal clear pics! I'm excited to get my pool startup to the 'maintain' part!!!!
 
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Good morning!

so.....drumroll.....this mornings OCLT with equipment off yielded a 1.5PPM drop in FC again. Frustrated-I did a 25ml sample and got only a 0.8PPM FC drop. (not valid as I didn’t use that precision last night)

also took the opportunity with the pump off to take some more pics.

Help!?!? Am I off to Wally World to load up on a shelf of chlorine?

CBC9AADE-5111-4F69-824E-9DB2E7FA596E.jpeg
 

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