Painting vs Re-Plastering

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Tribromoisocyanuric acid (C3Br3N3O3) is a white crystalline powder.

It is similar to trichloroisocyanuric acid.

Preferred IUPAC name: 1,3,5-Tribromo-1,3,5-triazinane-2,4,6-trione.

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I found this Q&A on a Health Department website in Ohio:
I have an indoor pool. Should I use cyanuric acid? – No. It should never be used in indoor swimming pools, spas or hot tubs. Remember that CYA is intended to reduce the loss of free chlorine caused by the sun’s ultraviolet rays. Indoor pools are not exposed to direct sunlight and therefore, there is no benefit in adding CYA to the indoor pool water.

And similar advice on this Health Department website in Montana:
I have an indoor pool. Should I use cyanuric acid? – NO. Remember that cyanuric acid is intended to reduce the loss of free chlorine caused by the sun’s ultraviolet rays. Indoor pools are not exposed to direct sunlight and therefore, there is no benefit in adding cyanuric acid to the pool water or using products containing cyanuric acid such as trichlor or dichlor. In addition the Administrative Rules of Montana prohibit the use of cyanuric acid in indoor pools.

I'm assuming it is okay, then, to run our indoor pool using liquid chlorine only... no stabilizer. Following Pool Math guidelines, it looks like the ideal would be to maintain FC at 2-3 ppm without any stabilizer in the pool. Sound about right?
 
JPMorgan said:
I'm assuming it is okay, then, to run our indoor pool using liquid chlorine only... no stabilizer. Following Pool Math guidelines, it looks like the ideal would be to maintain FC at 2-3 ppm without any stabilizer in the pool. Sound about right?
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Yes, sounds good.

If you want, you can add sodium bromide to convert to bromine and continue to use liquid chlorine.

If the CC levels become a problem, I would add UV and only use UV when the CC was at 1.0 or higher.

Switching to bromine by adding 5 lb of sodium bromide might help if CCs become a problem.
 
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JamesW said:
If the CC levels become a problem, I would add UV and only use UV when the CC was at 1.0 or higher.
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Are CC levels more difficult to control in an indoor pool? Could I also just SLAM the pool if I get CC level above 1.0?

Thanks for your help on this. Another advantage of using liquid chlorine in the indoor pool is that we don't have to empty the chlorine tank when we close the outdoor pool. It will just stay in service for the indoor pool year round.
 
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JP - what does your health department say about cya?
That is all that matters. If they allow it use 30ppm cya.
Tfp recommends that indoor residential pools & covered/indoor spas maintain a cya of 30ppm - this is for bather comfort & to make the fc less harsh on equipment & surfaces. It also allows you to maintain higher fc which prevents walking a tightrope between too harsh & too low.
Cya having “no benefit” in an indoor pool is not true. You also mentioned there is some uv exposure so its use is warranted if allowed.
 
UV can go through some glass and glass can block UV, so it depends on the glass.

Different wavelengths of light are blocked or transmitted differently by different types of glass.

Also, it depends on how much of the light hits the water and for how long.

So, it might be zero UV exposure or some exposure.

What is the exact window model number?

Are the windows clean and free of internal condensation?

How many panes of glass per window?

Is there any type of tint on the glass?

Can you provide a 3 dimensional digital twin of the building with the correct latitude, longitude and orientation of the building?

This should allow you to run a computational analysis of the sunlight at any time of the year.
 
Illinois
TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER n: RECREATIONAL FACILITIES
PART 820 SWIMMING FACILITY CODE
SECTION 820.340 OPERATION AND MAINTENANCE​


Section 820.340 Operation and Maintenance
l) Chlorinated Cyanurates. The use of chlorinated cyanurates is subject to the following requirements:
2) When the cyanuric acid level exceeds the maximum permissible limit of 100 p.p.m., 50 percent of the water shall be drained and replenished with potable water until the cyanuric acid concentration is less than 50 p.p.m.​

 
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Well there you go! The world is your oyster!
If you’re already going to exchange water/drain for maintenance you can go for the chlorine set up (w/liquid feeders if you desire) and the option to go back to bromine using the 2step method is still there if needed. But I imagine having both pools be chlorine will be much less hassle & simpler to manage.
Then of course comes the best option- swcg….
 
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PoolStored said:
Illinois
TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTH
SUBCHAPTER n: RECREATIONAL FACILITIES
PART 820 SWIMMING FACILITY CODE
SECTION 820.340 OPERATION AND MAINTENANCE​


Section 820.340 Operation and Maintenance
l) Chlorinated Cyanurates. The use of chlorinated cyanurates is subject to the following requirements:
2) When the cyanuric acid level exceeds the maximum permissible limit of 100 p.p.m., 50 percent of the water shall be drained and replenished with potable water until the cyanuric acid concentration is less than 50 p.p.m.​

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Yes.... I am aware of this regulation in Illinois. This why I convinced our HOA to dump the trichlor feeder on our outdoor pool and install a liquid chlorine feeder. I let them know that we would likely have to dump half of the swimming pool and re-fill it 2 or 3 times a summer. That would cost around $3,000 in water alone... not to mention increased heating costs. However, this rule wouldn't have any impact on our indoor pool if we switch to liquid chlorine since I would keep CYA (if it's even allowed in an indoor pool in Illinois) at 30 ppm or less.
 
JamesW said:
UV can go through some glass and glass can block UV, so it depends on the glass.

Different wavelengths of light are blocked or transmitted differently by different types of glass.

Also, it depends on how much of the light hits the water and for how long.

So, it might be zero UV exposure or some exposure.

What is the exact window model number? I'll see if I can get that off of the window.

Are the windows clean and free of internal condensation? Yes

How many panes of glass per window? One large pane per window. I will post a photo.

Is there any type of tint on the glass? A little.

Can you provide a 3 dimensional digital twin of the building with the correct latitude, longitude and orientation of the building? I have no idea what a "3 dimensional digital twin" is. Elmhurst, IL coordinates are 41.8995° N, 87.9403° W. The windows in the pool area face southeast.

This should allow you to run a computational analysis of the sunlight at any time of the year. Sounds complicated.
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I'll post a photo of the indoor pool area. Seems like the simple approach (if it's allowed) would be to put a little CYA in the water (20 ppm?) to give it a little protection from any UV exposure it may be getting. I still need to hear from the state re: using CYA in an indoor pool to see if it is even allowed.
 
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Is this a viable option for our indoor pool? Run the bromine feeder until 50 lbs of bromine tablets are used up. Then, turn off the bromine feeder and switch to the liquid chlorine feeder. Our main goal is to extend the period between water changes. Using solely bromine tabs, we go through about 75 pounds of tabs per year. As I understand now, the DMH build up in the pool after using 75 pounds of bromine tablets makes annual water changes necessary. Could we go 2-3 years between water changes by switching to liquid chlorine after using up 50 lbs of bromine tabs? Just curious if this approach could work...
 
I would mostly avoid bromine tabs.

The UV exposure is probably minimal based on the amount of sun that actually gets to the water.

The glass might block all or most of the UV, so I would consider it to be 0 to low UV exposure.
 
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JamesW said:
I would mostly avoid bromine tabs.

The UV exposure is probably minimal based on the amount of sun that actually gets to the water.

The glass might block all or most of the UV, so I would consider it to be 0 to low UV exposure.
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Do you think we could drain the pool less often... maybe every 2 or 3 years... by switching to liquid chlorine and running the pool without any stabilizer? As I said before, we already have most of the equipment needed (controller, chlorine feeder). We would just need a pump and some tubing to switch over to chlorine.
 
JamesW said:
The UV exposure is probably minimal based on the amount of sun that actually gets to the water.

The glass might block all or most of the UV, so I would consider it to be 0 to low UV exposure.
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Would this be a good test for UV exposure?
  1. Wait for a sunny day and test the bromine in the pool before sunrise.
  2. Close the pool to swimmers on that day.
  3. Turn off the bromine feeder
  4. Test the bromine level again after sundown.
  5. If bromine loss is negligible, then I could assume very little UV exposure.
Make sense?
 
JPMorgan said:
Do you think we could drain the pool less often... maybe every 2 or 3 years... by switching to liquid chlorine and running the pool without any stabilizer?
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I would probably go SWG.

I would use some stabilizer (20 to 30 ppm) if you use chlorine.

You can add sodium bromide later if you want to see how that goes.

You can start with no sodium bromide and then add about 1 lb to see how that works and then maybe 1 more pound etc.

At low bromide levels, you can have a partly chlorine and partly bromine pool.

See if you get CCs and if the CCs accumulate, I would add UV and only turn the UV on to eliminate the CCs.

I would do routine dilution based on the number of swimmers.

With daily dilution, you can eliminate the need to ever drain the pool.
 

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