first test with TF-100, need advice

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david11050

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May 22, 2013
15
Fort Salonga, NY
Just opened the pool yesterday and the good news is the water is clear and I can see to the bottom at the deep end.

After reading through pool school, I made the decision to switch from running back and forth to the pool store with water samples and blindly following advice and using the stores chemicals to ordering the TF-100 last week and switching to the BBB method. The TF-100 arrived just in time, ordered it wednesday and it arrived in saturdays mail, very quick delivery. Carefully performed my first test this morning with the following results:

CL: 0
pH: 6.8
FC: 0
CC: 0
TC: 0
TA: 80
CH: 180
CYA: 100

The pool calculator says with a FC, CL normal 8-13 and shock 25. Another option is to lower CYA by replacing 60% of water.
Question 1:
Is CYA of 100 workable or should I drain and replace 60% of the water now?

Assuming I do not drain (the route I am inclined to go with) the pool calculator says I need:
bleach: 19 96oz jugs
borax: 4.4 76oz boxes
baking soda: 10 lbs

I am about to go out and buy all of this.
Question 2:
What order should I add them? My understanding is I should balance pH first, correct? Then shock.

Then an hour later start adding bleach over a return at the deep end.
Question 3:
I read I should pour it slowly, a minute or two per jug. How long should I wait between adding jugs of bleach?

Thanks in advance for the help.
 
Welcome to the forum. :lol: Lower your CYA. Through a series of partial drains, bring your CYA down to a manageable 50 ppm......managing a pool with a CYA of 100 (it could be more) is almost impossible to do well.
 
Most of the common CYA tests will report any number over 100 as 100, so there is no telling what it actually is.

There is a similar issue with the PH, since the common PH tests reports anything below 6.8 as 6.8.

If you can get started right away, do the water replacement first, then PH, then chlorine.

There is no need to wait between bottles of chlorine.
 
Welcome to the forum :wave:

The CYA test will only test up to 100 and read anything above 100 also as 100. So, it could be 200 or 300 :shock:

So, I suggest you re-do the CYA test using a 50/50 mix of pool and tap water, then double the result ... that will allow you to maybe get a better estimate, especially if it is > 100ppm.

Skip the baking soda as your TA at 80 is just fine. pool-school/recommended_levels

Yes, pH first. Then shock (after you confirm that CYA level).

How long should I wait between adding jugs of bleach?
Click to expand...
No waiting, just add one after the other.

Edit [dang, Jason is fast, sorry for any duplication}
 
Thanks for all of the quick replies.

I am going to bite the bullet and start draining. Sure beats buying, transporting and carrying 19 jugs of bleach.

duraleigh said:
Lower your CYA. Through a series of partial drains
Click to expand...
So I should do a series of drains. Is there a risk to doing one massive drain? If yes, what is a safe level, lets say inches below the skimmer baskets that I should drain to, then refill and repeat?
 
Butterfly said:
So, I suggest you re-do the CYA test using a 50/50 mix of pool and tap water, then double the result ... that will allow you to maybe get a better estimate, especially if it is > 100ppm.
Click to expand...

I tested using 50% pool and 50% tap water in the CYA mixing bottle. I was able to completely empty the CYA bottle into the testing tube, filling it to the top and still see the black dot. Was not sure what to make of this?

This made me second guess my first CYA test, so I re-tested the CYA with the test kit method, pool water up to the bottom of the label then R-0013 to the top of the label. Shook it, waited a minute and shook it a few more times. This time when filling the tube the black dot disappeared at 90. And I was squinting with one eye watching the black dot to get it that far.

So after the two tests, I think I can safely say my CYA is in the range of 90 - 100.
 
david11050 said:
Since yesterday, I did my estimate of a 1/3 water drain and refill. Then let the pump circulate the water and re-tested CYA (twice). Both readings show a CYA of 60. Making progress. Since we are shooting for 50, I just started a second drain and refill.
Click to expand...
If the water is clear, I wouldn't bother. CYA will come down slowly through splashout and backwashing. You'll just need to maintain a slightly higher minimum FC.
 
I was half way into my last drain/refill when I read the last post and since I do not backwash (cartridge filter) I figured I would let it complete. Now my test results are as follows:

CL: 0
pH: 6.8
FC: 0
CC: 0
TC: 0
TA: 110
CH: 180
CYA: 50

I picked up bleach, borax and baking soda this afternoon and will start tonight.

So I will raise pH before shocking. At this point, should I aim to raise it to the 7.2 minimum or 7.5 (lower end of ideal range)? When re-testing the pH, how long after I add the borax should I re-test to confirm I have hit the target? Then I will slowly add all the bleach (7 jugs 121 oz at 8.25%) for a target FC of 16. Am I missing any steps?
 

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I'd aim for about 7.2 and not even worry about testing it if you're relatively sure of your volume. With a TA of 110 the pH will tend to rise a little.

Don't go too slowly with adding the bleach. Get it in there pretty quickly. I hope you got plenty on hand too. :)
 
I added 4-76 oz boxes of borax and an hour later 7-121 oz 8.25% bottles of bleach as per the pool calculator. Let it circulate for another hour and re-tested to see what FC was at. pH, FC and TA were moved much more than expected.

CL: > 5
pH: 8.2
FC: 32
CC: 0
TC: 32
TA: 320
CH: 180
CYA: 40

Wow, I have always had a hard time getting pH and Alkalinity to go up, never seen it this high. Where might I have gone wrong? I followed the pool calculators suggestions.

As for pool volume, a few pool professionals have estimated my pool at 35K gallons. Even if we go lower than estimates with 30K gallons, could that account for the drastic increases?

Was shooting for a FC of 16 but got 32. Shooting for pH of 7.2 and now its the highest reading 8.2. And TA shot up from 110 to 320.

In pool school I read testing pH is not accurate when shocking. Could this account for the very high readings in pH and TA with this test? Or are pH and TA so far off, that it needs to be corrected?
 
Don't panic, there's nothing that can't be fixed.

Just a note; so called "pool professionals" routinely over estimate pool volumes. Sometimes by a lot.

If it's 35k gals I get 7 jugs of bleach too.

The first thing I would do is re-run the tests. Except the pH test. We know it'll read high with the FC that high.
 
Thanks, good advice to re-test, looking much better. Re-tested when I got home last night with the following results. This was 24 hours after adding borax and bleach with the pump running continuously:

CL: > 5 (looks dark yellow while the last test was more orange)
pH: 8.2
FC: 16.5 (the number I was shooting for to start with)
CC: 0
TC: 16.5
TA: 110 (back to my baseline before adding borax and bleach)
CH: 170
CYA: 40

So things are looking much better than my test 24 hours prior. FC is the target shock amount, TA back within range. Not sure if I tested too soon after adding chemicals or maybe a testing error on my part.

The only thing that stands out now is the pH of 8.2 (was shooting for 7.2). Is this not an accurate test with a FC of 16.5? What level does FC have to drop down to for an accurate pH test?
 
FC levels came down over the weekend and pH has been reading 7.8 (was reading 8.2 with high FC levels). Had strong sun over the weekend followed by rain on Monday. My full set of test results are now:

CL: 1
pH: 7.8
FC: 1.5
CC: .5
TC: 2
TA: 120
CH: 140
CYA: 30

I added bleach to bring FC into the non-shock range of 2 to 6. Is there anything else I need to adjust?

Is pH of 7.8 OK now? Is a TA of 120 OK?

When going to the local pool store over the past two years (they must miss me now), I was told I needed Calcium levels above 200 since I have a heater. Something about possible damage to heater parts??? Is there any truth to this? Or any other reason I should raise my CH level? Or is CH good at 140?

Thanks again for all of the help offered here. :)
 
david11050 said:
FC levels came down over the weekend and pH has been reading 7.8 (was reading 8.2 with high FC levels). Had strong sun over the weekend followed by rain on Monday. My full set of test results are now:

CL: 1
pH: 7.8
FC: 1.5
CC: .5
TC: 2
TA: 120
CH: 140
CYA: 30

I added bleach to bring FC into the non-shock range of 2 to 6. Is there anything else I need to adjust?

Is pH of 7.8 OK now? Is a TA of 120 OK?

When going to the local pool store over the past two years (they must miss me now), I was told I needed Calcium levels above 200 since I have a heater. Something about possible damage to heater parts??? Is there any truth to this? Or any other reason I should raise my CH level? Or is CH good at 140?

Thanks again for all of the help offered here. :)
Click to expand...
You've fixed the FC. pH is still good, but expect it to need adjusting in a day or two. Just as an aside, human tears are about 7.4 -7.5. You don't need CH raised any with your vinyl pool.
 
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