Pool setup following water replacement?

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E

ErniesPool

0
May 22, 2013
127
Dallas, TX
I inherited a pool maintained by a pool service. Last December I had to dump half the water to get CYA down. Again, this month I had to dump about 2/3 of the water to get rid of CYA that apparently was in the pool walls and pipes.

I have had it with stabilized dichlor and trichor, have removed the floats from the pool, and am moving to liquid bleach as recommended on this forum.

Here are my test numbers as per a Taylor test kit following refilling and running the pump for 24 hours (and adding about 200 oz of 8.5% bleach late in the afternoon):

FC - 0
CC - 0
CYA - 55 (down from 150)
pH - 7.6
CA - 270
Tot AL - 70
25,000 gal in-ground plaster pool
Pool is crystal clear and beautiful.

With the pool now refilled, I cannot seem to hold any chlorine in the pool. If I add a jug of bleach, the FC comes up but a few hours later, nothing. I am just assuming the chlorine is being used up by organisms in the new and remaining old water. ???? Otherwise, where is it going?

The Taylor book recommends shocking the pool to 30 when the water has been changed. This will require, according to the pool calculator, about $30 of bleach for this one supershock! That seems excessive to me, since I am not combating high CC and doing breakpoint chlorination.

Can someone recommend what level of chlorination (ppm) I should shoot for to shock the pool? I can use the calculator from there.

Also, how much hypochlorite (jugs of liquid bleach 8.25%) should I anticipate needing each week given light usage of the pool?
 
Look over the charts and stick with the recommended shock ppm in pool school.
pool-school/chlorine_cya_chart_shock

30 ppm that Taylor recommends may be a little excessive for CYA of 55. There's no need to raise it too high and risk damage or waste money on extra bleach. From there follow the shock process outlined in pool school.

As far as how many gallons of bleach you will need; each pool is different depending on various factors like sun exposure, bather load, etc... Only time will tell what your oasis will require on a weekly basis.
 
I would stick with the results from your Taylor test kit and follow the instructions to the T for Shocking based on the info. from pool school.

The whole point with a good test kit is that you can put a number to what is wrong and then correct it with a proven method. It's all in the math.
 
OK. I see what is going on. Thanks to all for advice. I did not have a full understanding of the shock process. I thought it was a one-shot deal. The idea is to maintain the shock level until the oxidation process is complete. Headed to my big box store to load up on hypochlorite and initiating the shock process.
 
OK. I see what is going on. Thanks to all for advice. I did not have a full understanding of the shock process. I thought it was a one-shot deal. The idea is to maintain the shock level until the oxidation process is complete. Headed to my big box store to load up on hypochlorite and initiating the shock process.
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Excellent post, p_d. Too many people never quite understand that (some simply don't want to believe it) and they struggle forever trying to clear their pools.

We have moved you to the front row of the class for being a quick learner and it will be hard to refer to you by your username.....no longer applicable. :mrgreen: :mrgreen:
 
duraleigh said:
OK. I see what is going on. Thanks to all for advice. I did not have a full understanding of the shock process. I thought it was a one-shot deal. The idea is to maintain the shock level until the oxidation process is complete. Headed to my big box store to load up on hypochlorite and initiating the shock process.
Click to expand...
Excellent post, p_d. Too many people never quite understand that (some simply don't want to believe it) and they struggle forever trying to clear their pools.

We have moved you to the front row of the class for being a quick learner and it will be hard to refer to you by your username.....no longer applicable. :mrgreen: :mrgreen:
Click to expand...

You spoke too soon. Here is my question now. I'm waiting until late this afternoon to begin the shock to take advantage of the lack of UV burnoff. In looking at the pool chart and the Taylor test kit, I will need about 20 ppm chlorine to do the shock. To test this level I will need 40 drops of reagent from my kit!!! Further, the shock directions say maintain the shock level until one loses only 1 ppm overnight. I will have to order reagent by the gallon to comply with these instructions.

What am I missing here????

Further, I am assuming that the chlorine will disappear through UV exposure during the day (somewhat stabilized by the cyanuric acid). So, is the idea to measure the oxidation rate in the pool without UV until it stops depleting chlorine, and then let the UV reduce the chlorine to a level safe for swimming???

Don't mean to be grumpy here, but if that is what the shock instructions mean, why don't they just say that?

:(
 
I will have to order reagent by the gallon to comply with these instructions.
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How often do you intend to test?

With a CYA of 55, you will lose some of the FC to the sun but, mostly, the FC will do it's job consuming organics.
So, is the idea to measure the oxidation rate in the pool without UV until it stops depleting chlorine, and then let the UV reduce the chlorine to a level safe for swimming???
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I'm trying, but can't understand what you are asking other than to say it is safe to swim in FC up to shock value
 
duraleigh said:
I will have to order reagent by the gallon to comply with these instructions.
Click to expand...
How often do you intend to test?

With a CYA of 55, you will lose some of the FC to the sun but, mostly, the FC will do it's job consuming organics.
[quote:14rcgk0z] So, is the idea to measure the oxidation rate in the pool without UV until it stops depleting chlorine, and then let the UV reduce the chlorine to a level safe for swimming???
Click to expand...
I'm trying, but can't understand what you are asking other than to say it is safe to swim in FC up to shock value[/quote:14rcgk0z]

Let's say I just put in the computed dose of chlorine. After the sun goes down, I will get a free chlorine reading (I have no bound chlorine). I will adjust to bring it to roughly 20 ppm. Tomorrow morning I will read again. Am I looking for just less than a 1 ppm change!? OK. Two possibilities:

a) The reading is less than 1 ppm different (I doubt the test kit is even that accurate, but ...). I am done. So, question a) is: is it safe to swim with 20 ppm chlorine in the water or do I wait until the sun or something else reduces the chlorine level??

b) The reading is more than 1 ppm different than the night before. So, I calculate and replace the depleted chlorine. Wait til the next day (because the sun will kill some of it and I cannot differentiate between UV depletion and oxidation with other matter). Test again. Either add back the missing chlorine or go to outcome a). It seems I am looking for a working chlorine level of 4 ppm. The sun and other stuff will slowly take it down to this to 4 ppm until the next dust storm blows in or we get another downpour. I guess the question again is, is it safe to swim in the 20 ppm chlorine level??
 

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pool_dufus said:
Further, I am assuming that the chlorine will disappear through UV exposure during the day (somewhat stabilized by the cyanuric acid). So, is the idea to measure the oxidation rate in the pool without UV until it stops depleting chlorine, and then let the UV reduce the chlorine to a level safe for swimming???

Don't mean to be grumpy here, but if that is what the shock instructions mean, why don't they just say that?

:(
Click to expand...
You are correct.

Because even when we try to describe it in vocabulary a 5 year old can understand, an unbelievable number of new people here still don't get it.

It's not that people aren't intelligent, they just have a really hard time making the leap from the pool store way of doing things.
 
It is safe to swim up to shock level. I'm not sure you completely understand the shock process. You want to get up to shock level and keep it there until you pass all 3 criteria. The criteria are <1 ppm loss overnight, CC<.5, and pool is clear. This involves testing up to once an hour if possible, but definitely more than once a day.
 
JohnN said:
It is safe to swim up to shock level. I'm not sure you completely understand the shock process. You want to get up to shock level and keep it there until you pass all 3 criteria. The criteria are <1 ppm loss overnight, CC<.5, and pool is clear. This involves testing up to once an hour if possible, but definitely more than once a day.
Click to expand...

At 40 drops of reagent per test (at my shock level), thats a LOOOT of reagent, John!
 
like the Visa commercials...
tf-100 xl option...$15
20 gallons of liquid chlorine....$40
a sparkling oasis....priceless

using the methods on this forum are labor-intensive at first, but they work, and are a whole lot cheaper than getting pool stored.

your use of reagents will drastically drop off after you get your pool cleaned up.
 
I have the test kit TAYLOR K-2006 Complete Swimming Pool/Spa Test Kit FAS-DPD K2006 .

OK, end of this story is the following. I calculated the hypochlorite needed using the calculator and added it. For some reason the ppm level when 50% higher than the calculated amount (??). During the cloudy afternoon the pool consumed about 10 ppm of the chlorine. I measured the level as 22.5 ppm in the evening (20 ppm was my shock target given my CYA level). This morning, even after a rain last night, it was stable at 22 ppm. I consider the shock done. Now need to wait for some of it to burn off.

Can't convince my wife to get into the pool although I have tried to explain that it is safe especially for the kind of pool exercise she does. Realize this forum is for technical pool issues and not for family counseling. :-D
 
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