cost/benefit shocking pool
- Thread starter iam4iam
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I would say it starts to show up after about 3-5 days, and the test levels stop rising after 7-9 days, water temperature may be a factor here, but I have consistantly seen a measurable change a little over 7 days from dosing, ball park wise I would say 80% of level is reached in 7 days..
Just measured TA. It's 80-90 (80=pink; 90=red)
According to pool calc., it looks like washing soda might be my best bet since I'm on the low end of pH and TA.
So 16-32 oz of washing soda will counteract the pH reduction of the dichlor, but should there be any time lapse between the two additions?
Still very concerned about apparent "off the chart" CH! Is the blue really blue? (I still had light purple after 100 drops!) If it's truly supposed to be blue, I'll have to drain and replace some or the water will never be as clear as I want it to be!
According to pool calc., it looks like washing soda might be my best bet since I'm on the low end of pH and TA.
So 16-32 oz of washing soda will counteract the pH reduction of the dichlor, but should there be any time lapse between the two additions?
Still very concerned about apparent "off the chart" CH! Is the blue really blue? (I still had light purple after 100 drops!) If it's truly supposed to be blue, I'll have to drain and replace some or the water will never be as clear as I want it to be!
Swampwoman said:Hi there. I am also a first year, new-to-pool-school person who was flying blind. Because I hadn't started posting on TFP until AFTER I started the process, I went heavy on the bleach to maintain a state of shock and for a few days used color as my guide until the test kit came in and things really became more clear (in every sense, to me, to the pool water, etc.
I don't think I saw you mention it in your post, but you're backwashing frequently, right? Every time the filter is about 25% above it's normal operating psi (mine is normally in 15-20 range, it's a sand filter, hayworth, and likely same as yours as my pool is similar in size.) Mine was a swamp from a foreclosure, so at first I seriously had to backwash every half hour, but things got better rather quickly. During work day I came home at lunch to shock and to backwash in the beginning.
Just so you know, while I am now going to continue a little longer to clean up some organic staining, it took me about 12 days, constant filtering, and 58 gallons of bleach to date -- way more on the front end...much easier to maintain now. I am attaching pics to show you the color change (no pics from the weekend however until after the vacuuming to waste work on Monday).
Hope that helps. Perhaps you have your kit by now and are ready to hit hard, or perhaps you're already there. Do let us know, because this helps the next googler(And I resembled that remark)
So in terms of bleach cost, I think you're going to be fine with less than $100 worth since your pool is about the same size as mine and your filter sounds like mine (Hayward 220T sand). Be sure to clean out those baskets to keep it filtering well and backwash and keep the water level up and otherwise let TIME + BLEACH + TESTING do the work! Best wishes!
[attachment=0:3ndj26nj]12DaysofShockandAwe.jpg[/attachment:3ndj26nj]
great picture!
In your situation using Dichlor to help with the shock process is a great idea. Just make sure the product you buy is as close to 100% concentration as you can find. The nice thing about Dichlor is that the chlorine is already stabilized and dissolves quickly and easily. The CYA should register on your test as soon as the water has been fully circulated. Use the PoolCalculator to figure out how much total Dichlor you should add to get your CYA up to 20-30. You don't want to go much higher or the shock process will become increasingly more difficult.
After you pass the overnight free chlorine test and are done shocking, then you can bring your CYA up to the recommended level.
After you pass the overnight free chlorine test and are done shocking, then you can bring your CYA up to the recommended level.
iam4iam said:
Do not adjust ph during shocking. At FC levels above 10 ppm the ph test is not accurate. Do not worry about TA until you are finished with the shocking process. A TA of 80-90 is probably right where you want to be anyways.iam4iam said:
I think you may have a fading endpoint, from the extended test kit directions:iam4iam said:
What color is the solution before starting to starting to coundt R-0012 drops?
I assume dichlor in the pool calculator is referring to full strength? (Walmart carries it in 58%, 63%, and 99%!)
Yes it assumes the 99%. My opinion is to not mess with dichlor for now. Use liquid chlorine/bleach to dose to stay above your minimum FC level. Put some granular cya into a sock and put in front of the return. Shoot for a cya concentration of 20 to 30 ppm during the shocking process.iam4iam said:
Too late. But no worries. Sure, adding CYA would be "purer," but from what I've seen on this site, the only possibly undesirable side effects of dichlor are higher CYA (which I need anyway--assuming "not seeing the black dot" really means not seeing it) and lower pH, which I counteracted with washing soda as per pool calculator. At this point my chief concern is still my CH!
Fair enough, it is not what we typically recomend, but you can do it. For your 21000 gallon pool, you will need ~11 lbs of dichlor. This method can be less efficient since you can't add it all at once, so during the day your chlorine may be used at a higher rate then if you get the cya in there all at once.iam4iam said:
Again, do not adjust ph when over 10 ppm FC! This is important!iam4iam said:
You haven't answered my questions that I asked about what color the solution is before adding the R-0012? See my previous post.iam4iam said:
Sorry, I missed the post asking about the pre-0012 color and providing extended instructions. I'll investigate! (By the way, where can I find the extended instructions?)
It seems that I remember the "blue for a moment then fade back to red/purple" happen with the TA test (but maybe not with those colors). I assumed the drop that "counts" is the one where the color remained the "destination" color without fading back .
It seems that I remember the "blue for a moment then fade back to red/purple" happen with the TA test (but maybe not with those colors). I assumed the drop that "counts" is the one where the color remained the "destination" color without fading back .
No problem, link was in that post, but here it is again: extended test kit directionsiam4iam said:
With fading endpoints it can be hard to judge. Take a look at the sections in the extended instructions for both TA and CH.iam4iam said:
It seems like most of the tests have a "fade out" effect. I just checked my FC and CC for the first time since adding 4 lbs of dichlor (which was all I bought) a couple of hours ago and CC = 2FC = 8 making TC = what FC needs to be! I didn't think they'd eat it that fast! The pool is only moderately cloudy at this point and I can actually see the bottom (barely), so I thought ... Anyway, since bleach is all I have, round 2 for tonight ...
I didn't think they'd eat it that fast! The pool is only moderately cloudy at this point and I can actually see the bottom (barely), so I thought ... Anyway, since bleach is all I have, round 2 for tonight ...
Actually, I don't think I entered those numbers correctly, and I didn't write them down, either. I do know for sure, though, that CC was approx. twice FC. Off to add a few gallons of bleach!
Just keep at it, you will get there, the CYA from the 4 pounds of dichlor should help with the sun exposure
Just to make sure, with CYA test, black dot is supposed to disappear, not just fade, right? And I followed the link to "extended instructions" but didn't find what linen quoted. I did find the following alternative, which I'll try tomorrow.
"When high CH is anticipated, this procedure may be used:
Use 10 mL sample, 10 drops R-0010, 3 drops R-0011L, and multiply drops in Step 4 by 25."
Bedtime was hours ago! Maybe one last FC test first, though. (I knew this kit was going to cause me to lose sleep!)
"When high CH is anticipated, this procedure may be used:
Use 10 mL sample, 10 drops R-0010, 3 drops R-0011L, and multiply drops in Step 4 by 25."
Bedtime was hours ago! Maybe one last FC test first, though. (I knew this kit was going to cause me to lose sleep!)
Yes, under the correct testing conditions the CYA dot should be completely lost in the fog, as I understand it the correct testing conditions are in daylight with the sun to your back.
Good point about daylight. I just tried it under artificial light and got a reading way too high. Did someone posted that CYA from dichlor will show up on test sooner than straight CYA? Anyway, off to buy some more bleach. I should have bought some more bleach when I went to buy the dichlor, but I had 7 gallons. I just didn't expect the FC to be eaten so fast with pool semi clear like it is! Last reading was FC=2.5; CC=12.5! (I guess that tells me it's working. I'm really not going to get any sleep tonight! And I'm supposed to go teach some HS kids Hypothesis Testing in Prob/Stat tomorrow. Zombie teacher tomorrow!)