Add chemicals or drain first?

[babsh]

Add chemicals or drain first...
Been having algea trouble all year... biught a good test kit and found the following:
FC 7
PH 7.6
TA 60
CH 130
CYA 100
I assume the high CYA- plus high chlorine is leading to low calcium- not to mention the algae I've been fighting
Which do you suggest I do first: I add the calcium chloride to raise the CH or replace the water to lower the CYA?
Just re surfaced the pool last year - concerned about the low CH level messing up the gunite

 

[tim5055]

Re: High CYA question

Add chemicals or drain first...
Been having algea trouble all year... biught a good test kit and found the following:
FC 7
PH 7.6
TA 60
CH 130
CYA 100
I assume the high CYA- plus high chlorine is leading to low calcium- not to mention the algae I've been fighting
Which do you suggest I do first: I add the calcium chloride to raise the CH or replace the water to lower the CYA?
Just re surfaced the pool last year - concerned about the low CH level messing up the gunite

Is this your own testing or pool store testing?

If it's your replace water first. But,....... 100 is the limit of the CYA test, so you have to do a diluted test. While the full instructions are in the Pool School, here is the short version. Mix 50% pool water with 50% tap water. Use this mixed sample as your test water. If still at a 100 you will need to dilute more. Here is a great chart by JamesW to explain dilution rates and what you multiply the results by to get an approximation of your CYA level.

Pool water......Tap or distilled water.........Multiply result by

....1...................1................................2
....1...................2................................3
....1...................4................................5

 

[babsh]

Re: High CYA question

I'm using a Leslies Total pool care DPD test kit.
I tested it twice, kind of a different test than I've seen for CYA- had to fill a small vile with the mixture until the black dot at bottom can no longer be seen. Is this not an accurate test? I thought this was one of the kits suggested, but I didn't have my list when I went to the store.
Anyway, will diluting the water give me a more accurate reading? From our comment it doesn't look like to could go any higher than 100.
Thanks for your insight

 

[tim5055]

Re: High CYA question

I'm using a Leslies Total pool care DPD test kit.
I tested it twice, kind of a different test than I've seen for CYA- had to fill a small vile with the mixture until the black dot at bottom can no longer be seen. Is this not an accurate test? I thought this was one of the kits suggested, but I didn't have my list when I went to the store.
Anyway, will diluting the water give me a more accurate reading? From our comment it doesn't look like to could go any higher than 100.
Thanks for your insight

CYA can be higher than 100, but the test you are using only goes up to 100. When you get a 100 reading you need to do the diluted test to see how far above 100 it is.

This thread really should be split off as your own, not tacked on to an old thread. The moderators will probably split it off soon.

 

[tim5055]

Re: High CYA question

I'm using a Leslies Total pool care DPD test kit. I thought this was one of the kits suggested, but I didn't have my list when I went to the store.

It's close, it's missing the very important FAS-DPD chlorine test. Leslies is famous for saying this is the same thing or all you need. Order the FAS-DPD test from TFTTestkits.net and you are good to go.

 

[tim5055]

I assume the high CYA- plus high chlorine is leading to low calcium- not to mention the algae I've been fighting
Which do you suggest I do first: I add the calcium chloride to raise the CH or replace the water to lower the CYA?

So, back to your original question---

CYA or chlorine will not affect CH, but they do show why you have had constant algae problems.

Here is my suggestion:
Diluted CYA test to determine how much water you need to replace. In ATL you will want your CYA down around 30**
SLAM your pool to get rid of the algae
Raise CH up to 300 or so.


** Here are the recommended levels from Pool School
with Bleach
FC 3-7 (See CYA chart)
pH 7.5-7.8
TA 70-90+
CH 250-350
CYA 30-50

Speaking of Pool School, how much have you read? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

 

[babsh]

Thanks so much--I think they have split the thread- I'm a total newby and thougth I was doing right .. oops
I have read the ABC's as well as recommended pool chems- honestly wasn't sure how much was accurate info (who ever heard of putting liquid store bought bleach in their pool?) I see now I was very wrong.
I did print out the levels chart.
Plan on replacing water this week end and ordering the suggested addtl test.
BTW... CYA was at 186!!

 

[jblizzle]

How did you get 186? Did you somehow measure 93? Realize that the accuracy of the test in around +/-10-15ppm so no point trying to be that exact. Just pour the solution back and forth a few times and see if you are consistent.

 

[babsh]

OK now I'm totally confused... I did measure 93 drops. I filled the dispensing bottle with 1/2 tap and half pool up to the 7 line then filled it with the #13 the rest of the way. I used that and it took 93 drops for the black dot at the bottom of the vile to disappear.
What do you mean about pouring the solution back and forth a few times.
Sorry to be so ignorant on all of this

 

[jblizzle]

You do not count the drops for the CYA test. You look at the line on the side of the vial when the dot disappears.

Check out the tftestkits youtube videos: https://www.youtube.com/user/tf100testkit?feature=results_main

 

[babsh]

OK I tested it by diluting and then just as the test on you tube says... looks like its at 100. When I do the diluted test it says 90... test as shown on you tube it comes up at 100. I believe you said there was a 10-15 PPM + or minus. So should I go with a 100 or a 90 CYA in the pool math?

 

[pwrstrk]

If your diluted test was 90 you have to X that by 2. Your CYA level is 180.

 

[tim5055]

OK I tested it by diluting and then just as the test on you tube says... looks like its at 100. When I do the diluted test it says 90... test as shown on you tube it comes up at 100. I believe you said there was a 10-15 PPM + or minus. So should I go with a 100 or a 90 CYA in the pool math?

If you do the standard test and get 100 that means it's 100 or above.

Now you do the diluted test and get 90. But, in the diluted test you need to multiply your answer. If you did a 1 to 1 dilution, then multiply the answer by 2 to get 180.

 

[babsh]

Ohhhhhhh... now I see
OK so I'm at 180 I will plug that into the pool math board.
Then I should..
Take care of the CYA
then slam the pool
then add calcium?

 

[tim5055]

Ohhhhhhh... now I see
OK so I'm at 180 I will plug that into the pool math board.
Then I should..
Take care of the CYA
then slam the pool
then add calcium?

You got it. Any other way costs you more money.

You could add calcium now, but will pump it out when you fix the CYA.

You could SLAM now but it would take three times the amount of chlorine.

See the logic?

 

[babsh]

yes, totally... thanks so much- I was thinking it was the filter. Honestly I was saying ,what could these guys know the pool store doesn't..... then I saw what my pool store guy drives...lol

 

[tim5055]

then I saw what my pool store guy drives...lol

Remember who makes the payments

Now you don't support him anymore