New Pool - Skin rash ... help!

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flyinraptr

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Dec 10, 2010
22
Hello,

Brand new pool (about a month old) - saline, 17,000gallons. With the new pool - we received 1 month's worth of pool service. The pool service outfit is of course pushing for a long term contract - we've told them that we're still thinking about it. Long story short - getting rashes and have determined that it is from going into the pool. After some research on the Internet - looks like chemical imbalance with the pool water ... one thing i have noticed with the pool service company is they routinely add chemicals to the pool but i haven't seen them actually perform a water test. So it looks like we have to take matters into our own hands. Just started reading the Pool School - a lot to digest initially and i will be ordering a test kit. In the meantime, i tried using the basic test that we got with the pool - a Poolmaster 5-way test kit.

My results were as follows:
Chlorine = 1.0
PH = 8.2
Acid Demand = 7 drops | requires roughly 2.5 qts of acid
Total Akalinity = 19 drops ~ 190ppm

Checking the equipment - the Salinity is reading 2.9~3.0 gpl.

I'm still trying to get up to speed but it looks like the biggest issue is the Ph is way too high? Any other tips/advice would be greatly appreciated.
 
pH can dry out skin, not aware of any rash from it. You're reading pool school, so you'll be learning about CYA/FC and what is Combined Chlorine. You can try the search function for "rash" to get more ideas, including this link I posted last year: http://www.cdc.gov/healthywater/swimming/rwi/illnesses/hot-tub-rash.html

Cut right to the bottom line and go order a TF100 and a speedstir. In less than two weeks your water can be the envy of the neighborhood.
 
Richard320 said:
pH can dry out skin, not aware of any rash from it. You're reading pool school, so you'll be learning about CYA/FC and what is Combined Chlorine. You can try the search function for "rash" to get more ideas, including this link I posted last year: http://www.cdc.gov/healthywater/swimming/rwi/illnesses/hot-tub-rash.html

Cut right to the bottom line and go order a TF100 and a speedstir. In less than two weeks your water can be the envy of the neighborhood.
Click to expand...

Thanks - I already have the kit and speedstir on order. I was doing some research earlier today and there is quite a bit out there with regards to skin rash from pool water. Which is why i suspect the high PH may be the cause but hopefully with the TF kit we'll get a better idea.
 
flyinraptr said:
Hello,

My results were as follows:
Chlorine = 1.0
PH = 8.2
Acid Demand = 7 drops | requires roughly 2.5 qts of acid
Total Akalinity = 19 drops ~ 190ppm

Checking the equipment - the Salinity is reading 2.9~3.0 gpl.

I'm still trying to get up to speed but it looks like the biggest issue is the Ph is way too high? Any other tips/advice would be greatly appreciated.
Click to expand...

flyinraptr, you should try to get that TA down to 60-80 ppm. Right now with it being so high it will be difficult to keep the pH down especially if you have a SWG. Can you get a CYA reading for us? Also, your FC seems low, but without knowing your CYA level we cannot tell you what it should be.
 
I'd be willing to bet that the service either used test strips or took a sample back to the shop and added what that sample indicated at the next visit, a week later. (Sigh)

Yes, the pH and alk levels are high. The addition of acid will lower it. How much depends on a few things. If used a red indicator solution (typically 5 drops in a small vial), 8.2 is as high as it can test. The actual pH may be higher but won't be know until it gets below the testing limit.

High pH levels also inhibit the effectiveness of the chlorine. In addition to drying the skin, bio-baddies may be getting the opportunity to grow and multiply, contributing to the potential cause of the skin rashes.

Is your pool a concrete with plastered finish? This type of pool will see a continuous rise in pH as the plaster cures over the next several months. The SWCG cell will add to that. Start adding acid or any calcium in the water will begin to adhere to the pool surfaces. This calcium is also known as scale.

It's a good thing when homeowners are able and willing to properly test and feed their pool.

Scott
 
Thanks all for the responses. I mis-spoke about the pool age - it is now about 65 days old (time flies when your having fun) - the surface is PebbleTec and salt has been added. As i mentioned - i have TF100 kit on order - hopefully it will be here soon. The kit we received with the pool does not test CYA - as soon as the kit arrives - will test for it. After posting last night - i went ahead and added a little more than a qt of acid. I did a quick test this morning before heading off to work with a test strip and the ph level - was definitely lower than last night. The strips are hard to read and i know inaccurate but it looked like around 7.6 - i'll re-test again tonight using the basic kit - unless the new one arrives. At least i'll be able to compare with to last night's test and see if adding the acid made any difference.

A couple of things i failed to mention earlier - our water is crystal clear, we are in So. Cal and the day time temps lately have been in the 70s. The pool gets direct sun in the morning from around 10am til around 2pm - it is in the shade after 2pm. With a new pool - as you might imagine we've been using it a lot - i have the temp maintained at 90. Did notice this past weekend - the water level was on the low side - still above the skimmer line however - and i added about an 1.5" of water. We do not have a water conditioner on the house tap water - it is rather hard - will this effect the ph levels as well?

One question i have out of curiosity - i purchased the liquid acid - 1 gal jugs - what do you folks typically use to measure the amount to add to the pool?
 
> typically use to measure the amount to add to the pool

I don't measure anymore since my Simpool pH automates the dosing but when manually, in very small amounts, run pump, hour or two later re-test, add as needed small amount, rinse and repeat

You can use the pool calculator to figure out precisely what you need once you have full set of tests.
 
flyinraptr said:
...
A couple of things i failed to mention earlier - our water is crystal clear, we are in So. Cal and the day time temps lately have been in the 70s. The pool gets direct sun in the morning from around 10am til around 2pm - it is in the shade after 2pm. With a new pool - as you might imagine we've been using it a lot - i have the temp maintained at 90. Did notice this past weekend - the water level was on the low side - still above the skimmer line however - and i added about an 1.5" of water. We do not have a water conditioner on the house tap water - it is rather hard - will this effect the ph levels as well?

One question i have out of curiosity - i purchased the liquid acid - 1 gal jugs - what do you folks typically use to measure the amount to add to the pool?
Click to expand...
90!! :shock: Ooh, I'd hate to see your gas bill. I heated my pool up for a housewarming party last year - cost me about $100 for the three days it was running. And then no one got in because the weather turned cold and windy.... :|

Yes, hard water affects the pH, but mostly the CH and TA. You'll be using a lot of acid. I use one of these, from Leslies of all places.
14491.jpg

It's unbreakable, and you can look down and read it from the inside out, rather than trying to pour at eye level. Generally, I carry the acid jug to the edge, swish it in the pool in case there's any acid from the plastic case on the bottom of the jug (guess how I learned this) then set it down. I then scoop up a plastic bucket full of water, set that down, then measure my acid out over the bucket. Then the cup gets rinsed in the pool. Then the diluted acid gets poured in, near the returns so it mixes well.

Chlorine gets eyeballed. I can get pretty close to a quart guesstimated from a gallon jug. And when in doubt, go a little heavy.
 
Richard320 said:
flyinraptr said:
...
A couple of things i failed to mention earlier - our water is crystal clear, we are in So. Cal and the day time temps lately have been in the 70s. The pool gets direct sun in the morning from around 10am til around 2pm - it is in the shade after 2pm. With a new pool - as you might imagine we've been using it a lot - i have the temp maintained at 90. Did notice this past weekend - the water level was on the low side - still above the skimmer line however - and i added about an 1.5" of water. We do not have a water conditioner on the house tap water - it is rather hard - will this effect the ph levels as well?

One question i have out of curiosity - i purchased the liquid acid - 1 gal jugs - what do you folks typically use to measure the amount to add to the pool?
Click to expand...
90!! :shock: Ooh, I'd hate to see your gas bill. I heated my pool up for a housewarming party last year - cost me about $100 for the three days it was running. And then no one got in because the weather turned cold and windy.... :|

Yes, hard water affects the pH, but mostly the CH and TA. You'll be using a lot of acid. I use one of these, from Leslies of all places.
14491.jpg

It's unbreakable, and you can look down and read it from the inside out, rather than trying to pour at eye level. Generally, I carry the acid jug to the edge, swish it in the pool in case there's any acid from the plastic case on the bottom of the jug (guess how I learned this) then set it down. I then scoop up a plastic bucket full of water, set that down, then measure my acid out over the bucket. Then the cup gets rinsed in the pool. Then the diluted acid gets poured in, near the returns so it mixes well.

Chlorine gets eyeballed. I can get pretty close to a quart guesstimated from a gallon jug. And when in doubt, go a little heavy.
Click to expand...

LOL - Actually we haven't received a gas bill since water went into the pool - should be any day. Our pool builder told us that if we use it alot - it is cheaper to maintain it at certain temp than let it cool off and re-heat. I guess we'll see how long that lasts after we receive the bill! We just got the electric/water bill which was $600 but that includes the initial filling of the pool. Which brings up a question - with a 17k gallon pool - how long should the filter run on a daily basis?

The TK100 hasn't arrived yet - so re-tested with the basic kit - numbers changed slightly ...
Chlorine was 1.0 yesterday - tonight it looks more like 1.5ish - not quite 2.0
PH was 8.2 yesterday - tonight looks more like 7.8
Acid Demand was 7 drops yesterday - tonight it was 4 drops
Total alkalinity was 190ppm yesterday - tonight it is 170ppm

The water level is a little low - so will be adding more acid and water tonight and re-testing tomorrow.
 

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flyinraptr said:
Our pool builder told us that if we use it alot - it is cheaper to maintain it at certain temp than let it cool off and re-heat.
Click to expand...
That's actually not true, but the difference isn't that noticeable unless the time the temperature is low is long enough. The pool loses heat at a faster rate when the temperature of the water is higher so the heater will be on longer to maintain that temperature. If you were to let the temperature drop, then the heat loss slows down as the water temp drops so the total amount of heat needed to get the temperature back up is less than that needed to maintain it at the higher temp.
 
chem geek said:
flyinraptr said:
Our pool builder told us that if we use it alot - it is cheaper to maintain it at certain temp than let it cool off and re-heat.
Click to expand...
That's actually not true, but the difference isn't that noticeable unless the time the temperature is low is long enough. The pool loses heat at a faster rate when the temperature of the water is higher so the heater will be on longer to maintain that temperature. If you were to let the temperature drop, then the heat loss slows down as the water temp drops so the total amount of heat needed to get the temperature back up is less than that needed to maintain it at the higher temp.
Click to expand...

Interesting point - not sure i totally buy into it. Last month without heating - it our pool temp dropped to around 57. To heat it to 90 - it took roughly 10 hours. So lets say we only heat the pool for the weekend - it would be 10 hours of heating plus whatever additional time to maintain through the weekend. So the question is whether the heater runs that long during the week maintaining the temp at 90. We have the remote control panel inside the house - it has a red light indicator when the heater is running .... naturally i'm not around all day to watch it but i would be surprise if it runs for 10 hours for the week maintaining the temp. I rarely see it running. It would be an interesting test however. And depending on our next gas bill - we may have to find out! :-D
 
Once you find out your CYA levels I would shock the pool to disinfect the water, rashes are not always caused by imbalance. We had a bad case of swimmers ear (all of us) here at my house last year and it took a week of shocking, scrubbing the pool all over and cleaning all the pool equipment to get rid of it, once the pool was clean and kept in good balance we never had another problem. I would assume nothing until you get the pool under control chemically and disinfected after a proper shock, its very important to you and your family's health to start at zero.

Pool water clarity is only a visual thing, proper sanitation is another.
 
4jaw bring up a good point...a properly balanced and sanitized chlorine pool should be clear and have only a slight "clean white sheets" chlorine aroma :mrgreen: If you have a strong chlorine odor, there is a good chance your CC level may be high, but the TF100 will confirm that when you receive it.

Also, what chemgeek mentioned is in fact true, otherwise there would be no need for programable home heating/cooling thermostats that are so popular today and pools are by far less efficient vs an insulated home. You likely are not seeing the heater run that much as it's doing most of the work overnight when temps drop.
 
flyinraptr said:
Interesting point - not sure i totally buy into it. Last month without heating - it our pool temp dropped to around 57. To heat it to 90 - it took roughly 10 hours. So lets say we only heat the pool for the weekend - it would be 10 hours of heating plus whatever additional time to maintain through the weekend. So the question is whether the heater runs that long during the week maintaining the temp at 90. We have the remote control panel inside the house - it has a red light indicator when the heater is running .... naturally i'm not around all day to watch it but i would be surprise if it runs for 10 hours for the week maintaining the temp. I rarely see it running. It would be an interesting test however. And depending on our next gas bill - we may have to find out! :-D
Click to expand...
I've measured the gas usage difference and it's quite noticeable if the pool isn't used/heated for an extended period of time. It's also physics, so let's do an example to make this clear. I'm sure you would agree that the pool loses heat faster when the water temp is much warmer than the air temp. In fact, the rate of heat loss is proportional to that temperature difference, all else equal. So let's say that the air temperature is 55ºF and you want the pool heated to 90ºF. The amount of heat (energy) needed to heat the pool is proportional to the number of degrees the temperature must be raised, not counting the heat lost from the pool while it is being heated. That's key, as you will see, since maintaining a high temperature has significant heat loss, but you don't see it as any sort of temperature difference since that temp is being maintained.

So with our extreme example, let's assume that the rate of temperature loss from the pool in ºF/day is (Temp-55)/5 per day so when the pool is 90ºF this is a 7ºF loss rate per day if there were no pool heating. The pool actually cools off with an exponential decay since the rate of heat loss drops as the temperature difference between the pool water and the air gets towards zero. The formula for our example is T = 55 + 35*exp(-t/5).

Day 0: 90.0ºF
Day 1: 83.7ºF; 6.3ºF loss
Day 2: 78.5ºF; 5.2ºF loss
Day 3: 74.2ºF; 4.3ºF loss
Day 4: 70.7ºF; 3.5ºF loss
Day 5: 67.9ºF; 2.8ºF loss
Day 6: 65.5ºF; 2.4ºF loss
Day 7: 63.6ºF; 1.9ºF loss

So you can see that even though at 90ºF the rate of temperature drop is instantaneously 7ºF per day, as soon as the temperature drops, this rate drops as well. If we were to try and maintain 90ºF during the entire week, we would be heating the pool at a rate of 7ºF per day for 7 days or 49 degrees of heating. We wouldn't see any actual temperature rise because the heat added to the pool by our heater would equal the heat lost due to the water/air temperature difference. If instead we were to let the pool cool as above and then heat it rapidly from 63.6ºF to 90ºF, then this is 26.4 degrees of heating or 54% of the heat we would use if we tried to maintain the water at 90ºF. If the heating took a whole day to achieve, then the heat loss during that day would be roughly another 4-5ºF so call this a total of around 31 degrees of heating which is still lower than the 49 degrees of heating it takes to maintain the temperature. If it took 24 hours for our gas heater to do the equivalent of 31 degrees of heating, then the 49 degrees spread out over the week is a heater on-time of only (49/7)/31 = 23% so the heater doesn't "seem" to be on all that much, but it's cumulatively more because it's over an entire week.

The main reason that people miss seeing why it takes more heat to maintain the pool temperature is that this heat loss is seemingly invisible because the pool water temperature is not changing. When you heat the water from a lower temp to a higher temp, you see the temperature difference so assume that is must be a lot of heat compared to the "invisible" heating done to maintain water temp. Also, when maintaining the temp, the heater is only on part of the time, though over a longer total elapsed time while when heating from a cold temp it is on continuously until you get to the high temp.
 
Great information .... the feedback gives me confidence that maintaining the pool myself is the right decision. The water does not have a strong chlorine odor - nor do we have the burning of the eyes etc .... skin is really dry though. Still waiting on the new kit.

Chem geek - excellent explanation - appreciate it - that makes sense. Obviously - saving on heating costs is a good thing .... only downside ... is having to plan in advance to use the pool - but as we get closer to summer - shouldn't be a problem. Our backyard faces directly south - normally during the summer months - it has full sun all day - right now the sun is too low for all day sun. But i think we'll be changing our strategy of maintaining it at 90. Our outside temps lately have been fluctuating by 25 degrees or more between day and night - the day it was 75 and it got down to 48. So yeah - i would imagine the heater has been running mostly late at a night. Still kinda wondering how long the filter really needs to run ... about 17k gal ... originally it was set to 8 hrs and since we're maintaining temps i lowered it to 6.
 
2.9 to 3.0 gpl = 2900 to 3000 ppm... your salt level should be fine. :-D

Salt does not get used up by the Chlorine Generator so you may not need additional salt for a long time. A small amount of salt is lost to splash-out, but the primary loss is from rainwater dilution.

Please post a little more information about the type of pool (plaster, vinyl, fiberglass) as well as the make and model of your equipment: Pump, filter, SWCG etc. With this additional information, forum members can provide you with more detailed answers to your questions such as how long to run your pump (turnover rate), how to adjust your Salt Chlorine Generator and what to expect when balancing your water chemistry.

Enjoy that new pool !
:goodjob:
 
Well ... just got the TF-100 Kit. The CYA is 40, Chlorine is 3ppm, ph is 8.2, TA is 150ppm.

We had rain on Sunday and i did need to add water since the last water test. The TA is definitely lower than last week (190 ppm), the ph is still high.
 

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