What could cause a bumpy rash??

[Mdragger88]

I did think about offering our pool, though we live about 30 minutes to the east of this pool. (I work in the same town as the lessons.) I don't know that it would work for the instructor. Perhaps people would choose that over just cancelling the rest of the lessons if it came to that.

I have also sent the instructor the link to this thread, and I think she'll pass it on to the homeowner.

Ok, here are my test results:

CYA: Roughly 30 (The dot was pretty faint at that level, I would have to guess that if the tube were taller, it would have registered somewhere in between 20 and 30 and therefore round up to 30 anyway.
FC: 1
CC: .5-1 (It might have turned back to clear with one drop, but I wasn't totally sure so I added a second drop.)
PH: 8.6 (Yes, that high, checked with my meter and then the dye test and it was off the chart red.)
TA: 130
CH: 175 *

*The pool is completely tiled and grouted, every surface in it-walls, floor, etc). So do I assume that it would be treated like a plaster pool for the purposes of things like CH? If so, that is pretty low I think.

My guess is that the owner is assuming that 1 PPM chlorine is within the range and they'd naturally want it to be low to protect the babie's skin (I can see how that would be an easy conclusion to come to). So I'm thinking that probably the best bet would be to raise the chlorine to at least 6 PPM each day after the lessons, that would kill off all the baby pee and let it fall into an acceptable range by the next morning (though that should still be checked in the morning, at least for a while). Of course, using liquid chlorine to avoid adding more CYA as it seems to be about in range of recommendation for an indoor pool. Though maybe she could use up some of that bucket to avoid waste and still be in a decent range?

The 1ppm fc level is only 1ppm away from zero. Minimum for a cya of 30 is 2ppm. Target is 4-6ppm.
FC/CYA Levels
Running it at 1ppm is unsanitary - letting fc get too low during use risks person to person transmission of pathogens. Dosing higher afterwards does nothing to mitigate that risk.

I also see on that CDC page that PH out of range can contribute to hot tub rash, though it doesn't mention if the bacteria that cause it prefer it high or low. I do also see that high PH can cause skin itchiness.

So I texted the instructor and recommended she pick up some acid on the way there in the morning, and add enough to bring the PH down so that she isn't having that be a contributing factor to itchiness.

Great

The instructor said something about the homeowner thinking that a salt water chlorine generator was not recommended for their pool because of the tile. Is there something to that? I haven't seen anything like that here at TFP, other than if it were new plaster you have to wait a while before adding salt (and using the generator). This is not a new pool.

Some types of stone are just bad ideas to use for a pool - salt or not they will deteriorate. If its fine now it should remain fine with a swg. The low ch is liable to a worse effect on the surfaces/grout than the salt content will.

Also said that the homeowner was willing to consider switching to either bromine or baquacil (I don't remember which she said, are they different chemicals? Or is Baquacil a name brand for bromine?) Is there any advantage to that?

Bromine can be harsh for some - you also mentioned that there is some uv exposure for this pool. There’s nothing to protect bromine from uv like cya does for chlorine so it may not be the best solution in this situation.
Baquacil, SoftSwim, Revacil (biguanide) pools are expensive to maintain & often end up with trouble after a couple years (white water mold, pink slime, etc.) so it’s not recommended here. It is not the same as bromine although some components of the system contain bromine/bromide.

Bottom line is that it’s not the type/method of sanitizing that is to blame here. It is inadequate dosing of the current sanitizer.

 

[ajw22]

Ok, here are my test results:

CYA: Roughly 30 (The dot was pretty faint at that level, I would have to guess that if the tube were taller, it would have registered somewhere in between 20 and 30 and therefore round up to 30 anyway.
FC: 1
CC: .5-1 (It might have turned back to clear with one drop, but I wasn't totally sure so I added a second drop.)
PH: 8.6 (Yes, that high, checked with my meter and then the dye test and it was off the chart red.)
TA: 130
CH: 175 *

Was this sample take before the lesson or after?

*The pool is completely tiled and grouted, every surface in it-walls, floor, etc). So do I assume that it would be treated like a plaster pool for the purposes of things like CH? If so, that is pretty low I think.

Yes, a tile and grout pool needs CH like a plaster pool to protect the grout.

My guess is that the owner is assuming that 1 PPM chlorine is within the range and they'd naturally want it to be low to protect the babie's skin (I can see how that would be an easy conclusion to come to). So I'm thinking that probably the best bet would be to raise the chlorine to at least 6 PPM each day after the lessons, that would kill off all the baby pee and let it fall into an acceptable range by the next morning (though that should still be checked in the morning, at least for a while). Of course, using liquid chlorine to avoid adding more CYA as it seems to be about in range of recommendation for an indoor pool. Though maybe she could use up some of that bucket to avoid waste and still be in a decent range?

If you begin the lesson with 1ppm of FC you are likely having 0 FC by the end of the lesson.

You want to have at least 2 ppm of FC after to know that the water stayed sanitary the entire time.

The instructor said something about the homeowner thinking that a salt water chlorine generator was not recommended for their pool because of the tile. Is there something to that? I haven't seen anything like that here at TFP, other than if it were new plaster you have to wait a while before adding salt (and using the generator). This is not a new pool.

No.

Most plaster pools have waterline tile and tile around the spa. A SWG is perfectly compatible with a SWG.

Also said that the homeowner was willing to consider switching to either bromine or baquacil (I don't remember which she said, are they different chemicals? Or is Baquacil a name brand for bromine?) Is there any advantage to that?

No. Don’t go near bromine or Baqua. They are more trouble then chlorine.

 

[superdave5599]

So I'll adjust my recommendation to be adjust it to 5-6 ppm each day after the lessons, and check and adjust again if needed in the morning before lessons to make sure it's sanitary during them.

 

[superdave5599]

So I'll adjust my recommendation to be adjust it to 5-6 ppm each day after the lessons, and check and adjust again if needed in the morning before lessons to make sure it's sanitary during them.

My thoughts on adjusting up in the evening is primarily to help burn off all the CCs that come from kids peeing in the pool. And in the morning to make sure it's sanitary during the day.

 

[ajw22]

My thoughts on adjusting up in the evening is primarily to help burn off all the CCs that come from kids peeing in the pool. And in the morning to make sure it's sanitary during the day.

Raising the chlorine does not burn off CCs.

Chlorine created the CCs. CCs are burnt off from UV from the Sun or a UV system.

Does the indoor pool have a UV system running?

CC - Further Reading

www.troublefreepool.com

 

[Mdragger88]

So I'll adjust my recommendation to be adjust it to 5-6 ppm each day after the lessons, and check and adjust again if needed in the morning before lessons to make sure it's sanitary during them.

You wanna start with target level fc so you don’t risk broaching minimum before the lessons are over.
Testing before & after lessons will help determine what kind of fc demand is produced from a typical lesson.

 

[superdave5599]

Raising the chlorine does not burn off CCs.

Chlorine created the CCs. CCs are burnt off from UV from the Sun or a UV system.

Does the indoor pool have a UV system running?

CC - Further Reading

www.troublefreepool.com

I think it was this line in the "CC Further Reading" page that caused me to think that proper chlorine would "burn off" the CCs over time:

"...especially when following the TFP protocol because there's always enough FC to quickly deal with the little CC that forms. " In the algae question.

I did not note anything that looked like a UV system in the plumbing area. There are some skylights though, so I guess it gets a little UV.

 

[superdave5599]

You wanna start with target level fc so you don’t risk broaching minimum before the lessons are over.
Testing before & after lessons will help determine what kind of fc demand is produced from a typical lesson.

Right, that was what I was trying to say. Start the day at the high end of the target level (so between 5-6 ppm) and then check again at the end of the day and if necessary boost it back up to 5-6.

I just worded it with starting that cycle at the end of a day instead of the beginning of a day. But I was proposing checking it and adding liquid chlorine as necessary at the beginning and end of each day to make sure the chlorine level stays at the high end of the recommended amount. I'm throwing in the second check for the duration of lessons just because we can assume a lot of babies are peeing in there, so we want to make sure it never dips low.

I also mentioned to the instructor that a SWG would make all this much easier!

 

[JamesW]

An indoor commercial pool cannot be run just using chlorine, especially if the pool gets heavy use.

Chlorine might eventually break down CCs if more CCs were not continually being introduced, but the CCs keep getting introduced and they never go away.

If you have kids using a commercial pool, someone is going to pee in the water and that is just a fact that you need to accept and deal with.

 

[superdave5599]

It's an indoor private pool at a residence.

I presume the instructor is renting it (or some similar agreement) for the classes; she is not the homeowner.