Needing advice

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,404
Laughlin, NV
When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....
 

Jubenez

Well-known member
May 15, 2019
47
Indiana
I did that method. I think it is 70 or 80. My eyesight is not that good, I'll have my husband try but he isn't home in daylight hours.
At 70-80 would you dump or SLAM?
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
You can continue to SLAM without dumping you will just need to make your SLAM target 31ppm for your free chlorine. Harder to hold it there at a higher level
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,519
Northern NJ
I did that method. I think it is 70 or 80. My eyesight is not that good, I'll have my husband try but he isn't home in daylight hours.
At 70-80 would you dump or SLAM?

Don't agonize if it is 70 or 80. Round up the CYA test and call it 80. The test is only accurate to +/- 10 ppm anyway.

Long term you want to get your water down to CYA 30 to be more manageable. If fill water is not an issue then doing a water exchange now will lower your CYA and dump alot of the algae out. The SLAM Process should then go faster and require less chlorine.

You need to drain about 50%-60% of your water. You really don't want to drain a pool with an old liner. @mknauss can tell you how to do a water exchange.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,404
Laughlin, NV
Let's not talk drain yet when you added CYA recently due to it testing 0. I suspect your testing protocol for the CYA is an issue. You are staring at the dot. Don't do that. You will see it forever if you stare at it.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,404
Laughlin, NV
Liquid chlorine has no CYA.
So you might have had 20 ppm CYA to start. So now you have ~50. Use that for SLAM level FC. And test the CYA tomorrow using the process I described above.
 

Jubenez

Well-known member
May 15, 2019
47
Indiana
Liquid chlorine has no CYA.
So you might have had 20 ppm CYA to start. So now you have ~50. Use that for SLAM level FC. And test the CYA tomorrow using the process I described above.
So are you thinking I'm reading the CYA test incorrectly? I performed it 2 or 3 times today (with the same sample).
Would adding hth super shock (56% calcium hypochlorite) cause any issues?
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
So are you thinking I'm reading the CYA test incorrectly? I performed it 2 or 3 times today (with the same sample).
Would adding hth super shock (56% calcium hypochlorite) cause any issues?
Stop grasping for additional things to throw in the pool and just stick with liquid chlorine. Calcium hypochlorite has no benefits over liquid chlorine and has many drawbacks. Don't add more variables to complicate your situation. Keep it simple.
 

Jubenez

Well-known member
May 15, 2019
47
Indiana
Stop grasping for additional things to throw in the pool and just stick with liquid chlorine. Calcium hypochlorite has no benefits over liquid chlorine and has many drawbacks. Don't add more variables to complicate your situation. Keep it simple.
Okay you are right... it's just that I've added probably 50 gallon of chlorine to a pool that is still green. 😢 I will resist the urge!
 

czipper

LifeTime Supporter
May 12, 2014
82
Long Island, NY
You are in good hands here, these experts know what they are doing and really want to help. Take a deep breath (maybe a day off even, if it is bringing you to tears). Then take stock of your situation and everything you have learned and get back into it. If you are unsure, ask BEFORE you do.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
11,522
Evans, Georgia
I just want to clarify that you're testing your FC with how much pool water- 5cc? or 10cc?

If it is 5cc, each drop of 0871 = 1ppm
if it is 10cc, each drop of 0871 = 0.5 (which just means count all the drops then divide by 2)

Maddie :flower:
 

Jubenez

Well-known member
May 15, 2019
47
Indiana
You are in good hands here, these experts know what they are doing and really want to help. Take a deep breath (maybe a day off even, if it is bringing you to tears). Then take stock of your situation and everything you have learned and get back into it. If you are unsure, ask BEFORE you do.
Thank you for the reassurance. I just had high hopes for this weekend :) I'm not giving up!
 

Jubenez

Well-known member
May 15, 2019
47
Indiana
I just want to clarify that you're testing your FC with how much pool water- 5cc? or 10cc?

If it is 5cc, each drop of 0871 = 1ppm
if it is 10cc, each drop of 0871 = 0.5 (which just means count all the drops then divide by 2)

Maddie :flower:
I'm using 10 ml water and 2 level scoops of the powder. Now I understand that a drop is equal to .5 ppm but initially i had it wrong (bad advice from local pool store).
Is it okay to test at 5 ml sometimes to save on drops? Maybe not right now bit after i get everything cleared up?
Thanks!
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
You can use 5mL for a quick check and during SLAM to save on re-agents but if you need to know a more accurate level then the 10mL or 25 mL samples are better choices. I use 10ml for routine testing and 5mL for SLAMing