couple questions from a newbie about CYA, chlorine, leaf stain

[eugchen]

my CYA is high, ~130, and my chlorine levels are low. used pucks for about a year now.

yesterday i drained half the pool and in the process now of adding water back in, and will add liquid chlorine.

1. i noticed a leaf stain at the bottom of the deeper end of the pool (1 day old) how do i get rid of this besides scrubbing as much as i can? it looks better but stain still there. is staining more prevalent with lack of chlorine? (image below)

2. how do i know how much liquid chlorine to add for a 12,000 gallon pool with low levels, and wanting to get it to normal levels?

3. help me understand something. these chlorine pucks are bad because they add chlorine and CYA into the pool. CYA necessary to prevent chlorine from being evaporated with sunlight, but when water evaporates and chlorine used up, the CYA stays in the pool. when you continue to do this, the CYA gets higher and higher, requiring a higher level of chlorine necessary to work in sanitation. do i have this right? but the "right way" i hear is to use liquid chlorine. if i do this, do i need to manually add CYA? when you do it this way, the CYA also stays in the pool and accumulates the same way right? eventually, will i have to drain the pool when the CYA gets too high like with my pucks?

 

[PoolStored]

1. i noticed a leaf stain at the bottom of the deeper end of the pool (1 day old) how do i get rid of this besides scrubbing as much as i can? it looks better but stain still there. is staining more prevalent with lack of chlorine? (image below)

Sustained normal chlorine levels should remove it. You can also use a puck and lightly go over the stain to remove it.


2. how do i know how much liquid chlorine to add for a 12,000 gallon pool with low levels, and wanting to get it to normal levels?
Follow this to figure out how much FC you need to have based on your CYA. Link-->FC/CYA Levels
Then use Pool Math to figure out how much chlorine to add to get to your FC target. Link-->PoolMath


3. help me understand something. these chlorine pucks are bad because they add chlorine and CYA into the pool. CYA necessary to prevent chlorine from being evaporated with sunlight, but when water evaporates and chlorine used up, the CYA stays in the pool. when you continue to do this, the CYA gets higher and higher, requiring a higher level of chlorine necessary to work in sanitation. do i have this right?

Yes.

but the "right way" i hear is to use liquid chlorine. if i do this, do i need to manually add CYA?

Yes, or use pucks until you get to your target CYA..

when you do it this way, the CYA also stays in the pool and accumulates the same way right? eventually, will i have to drain the pool when the CYA gets too high like with my pucks?

No. CYA degrades 5-10ppm per month. You will be adding CYA during the year. Additionally, if you evaporate 100 gallons, and add 100 gallons, your CYA will stay the same.
.

 

[mgtfp]

but the "right way" i hear is to use liquid chlorine. if i do this, do i need to manually add CYA? when you do it this way, the CYA also stays in the pool and accumulates the same way right? eventually, will i have to drain the pool when the CYA gets too high like with my pucks?

It's about the CYA that is in the water. Most of the chlorine you add via bleach will bond to the existing CYA and be protected from the sun. You don't have to add CYA everytime you add liquid chlorine.

Only a small fraction of the FC will remain as "active" chlorine that has sanitizing properties, but will also be susceptible to UV decay. But the chlorine bound to CYA still shows up as FC in the pool test kits. That's why the FC target depends on the CYA level: FC/CYA Levels

You maintain CYA in the recommended range. If it gets too low with water dilution, and a certain degree of CYA-decay over time, you add more.

 

[mgtfp]

how do i know how much liquid chlorine to add for a 12,000 gallon pool with low levels, and wanting to get it to normal levels?

With PoolMath

 

[mgtfp]

i noticed a leaf stain at the bottom of the deeper end of the pool (1 day old) how do i get rid of this besides scrubbing as much as i can? it looks better but stain still there. is staining more prevalent with lack of chlorine?

Chlorine should bleach those stains out if they are organic. Try rubbing a puck on it to speed it up.

 

[eugchen]

so the idea is to use liquid chlorine and add CYA when needed. in summer will need more...winter less. can use pucks to add CYA until get to desired CYA levels. once at these correct levels, then they will pretty much stay there, degrading a bit each month right? so using the

Free Chlorine and Cyanuric Acid Relationship Explained​

so if my CYA = 60, and i want Maintain my pool using liquid chlorine, then the calculator says i need minimum of 5 and target range 7-9.

so basically, i need liquid chlorine to get FC into 7-9 range, assuming CYA stays at 60?

do i have this right?

 

[mgtfp]

Pretty much. The golden rule for FC is: Err on the high side. The minimum is the last frontier you never want to cross. If In doubt, set your target higher, rather than lower.

 

[eugchen]

ok got the TFT100 finally and ran my tests. here are my results. keep in mind that my pool seems ok, with a light yellowing on some parts of the wall and corners every few days. i live in LA (socal area) where the water temp is cooler these days.

keep in mind my CYA a few weeks ago was around 130 and i drained what i believe was around half the pool and refilled.

DAILY TESTS
Chlorine - around 4ppm
pH - 7.8

WEEKLY TESTS
Chlorine Drop test - FC - 6
Combined Chloramines (CC) - no CC's (soln stayed clear)
Total Chlorine - is this the 4 + 6 = 10ppm?

Calcium Hardness Test - 350ppm (needed 14 drops)
Total Alkalinity Test - 90
CYA test - kinda subjective, but between 70-80, probably closer to 80

please advise me on what i need to do or if my pool is ok. thank you

 

[PoolStored]

Congrats on the KIT!!!!!!

Following this tool (link at end of sentence), your FC should be 9-11 with CYA of 80. Link-->FC/CYA Levels

Given the yellowing, I predict that you have algae. Do the Overnight chlorine loss test (OCLT)...this will tell us if you have algae. Link-->Overnight Chlorine Loss Test

If you FAIL OCLT, then you need to follow the SLAM process to clear the algae. Link-->SLAM Process

If you PASS OCLT, then you need to raise and maintain your FC to keep it between 9-11.

All your other results are decent.

I would suspend using the daily FC test...it really only tells you if you have FC. Use the FAS-DPD powder FC test for daily FC testing. You can use 10ml sample for testing...each drop of re-agent is equal to .5 FC.

 

[eugchen]

what is free chlorine? is my total chlorine 10? or just the result of the chlorine drop test?

also, with the solution in the CYA drop bottle, can i keep that until the next time i want to use it? or does it degrade and i need to chunk it?

thanks on the other info by the way!!!! Ill work on it!

 

[PoolStored]

what is free chlorine? is my total chlorine 10? or just the result of the chlorine drop test?

Yes, just the result of the FAS-DPD powder drop test. That is FC (Free Chlorine). The only two "chlorine" test results that are important are FC and CC (combined chlorine). Total chlorine really doesn't mean anything and we don't use it. We use FC to maintain chlorine in the pool, and to keep enough for your CYA level using the FC/CYA tool. You don't need to worry about CC results, unless your CC => 1. If it is >=1, it is time to SLAM.

also, with the solution in the CYA drop bottle, can i keep that until the next time i want to use it? or does it degrade and i need to chunk it?

Why would you want to keep it. Once the test is over, it is over. If you want to test CYA again, re-do the test from the beginning. Keeping the resulting solution and testing it again in two weeks means nothing...because it isn't using current pool water. CYA will degrade in the pool over time...like 5-10ppm per month if you are not adding CYA or using tablets to chlorinate.

thanks on the other info by the way!!!! Ill work on it!

No worries. Happy to help.

 

[eugchen]

"Why would you want to keep it. Once the test is over, it is over. If you want to test CYA again, re-do the test from the beginning. Keeping the resulting solution and testing it again in two weeks means nothing...because it isn't using current pool water. CYA will degrade in the pool over time...like 5-10ppm per month if you are not adding CYA or using tablets to chlorinate."

DUH---sorry, stupid question hahaha

concerning FC, there are two FC tests right? one daily and one weekly? the daily one uses that black square thing (TF Comparator Block) where you match the color to the side right? and the weekly one uses the powder and the 10ml bottle? so you are saying from now one, dont use the black square thing (TF Comparator Block)? only use the 10ml and powder one?

the 10ml + powder is the FAS-DPD test?


im asking cause on the instructions under DAILY TEST, it says "the blue plastic box K-1000 contains a test kit for chlorine and ph..." i dont think i got a blue plastic box.

 

[eugchen]

also to perform overnight test, is 7 hours enough time? i cant be here in the early morning for the next week. i can do around now, 7pm (dark here) and again around 1pm. that is 6 hours apart. is that ok Or enough time?

 

[PoolStored]

concerning FC, there are two FC tests right? one daily and one weekly? the daily one uses that black square thing where you match the color to the side right? and the weekly one uses the powder and the 10ml bottle? so you are saying from now one, dont use the black square thing? only use the 10ml and powder one?

the 10ml + powder is the FAS-DPD test?

Yes. Use this for your daily testing.

im asking cause on the instructions under DAILY TEST, it says "the blue plastic box K-1000 contains a test kit for chlorine and ph..." i dont think i got a blue plastic box.

Can't help with you not receiving box...

also to perform overnight test, is 7 hours enough time? i cant be here in the early morning for the next week. i can do around now, 7pm (dark here) and again around 1pm. that is 6 hours apart. is that ok Or enough time?

Did you mean 1am? 6 hours is a bit tight...we recommend at least 8. Do the test...if you fail at 6 hours, you will fail at 8 hours. If you pass, then re-do when you can do it properly, and raise and maintain your FC at 9-11 until you can redo the test. Brush your walls daily for the next week until the proper OCLT if you pass.

 

[eugchen]

lol yes 1am. thanks.

was i supposed to get a blue box as well?

 

[PoolStored]

was i supposed to get a blue box as well?

My *guess* is that they used Taylor's instruction in the TF100 kit. The Taylor kit comes in a blue box, hence the reference. The TF100 comes with a clear box. I'd ignore it.

 

[eugchen]

gotcha! thanks!

 

[eugchen]

some other thoughts and questions i had....

1. is a CYA of 80 ok and manageable as long as im willing to keep my FC 9-11? or do i need to drain my pool again?

2. assuming i dont drain pool and deal with a CYA of 80, and i get FC up to 10, how long usually will that stay at 10 before i need to add more liquid chlorine? and i guess the idea when it goes down, i just need to add back enough liquid chlorine to get it to the 9-11 range?

 

[mgtfp]

1. is a CYA of 80 ok and manageable as long as im willing to keep my FC 9-11? or do i need to drain my pool again?

If you pass the OCLT, then CYA 80 is manageable. But I suspect you need to SLAM:

keep in mind that my pool seems ok, with a light yellowing on some parts of the wall and corners every few days.

That doesn't sound too OK to me. That sounds like a SLAM is in order, and this will be challenging with CYA 80. OCLT will tell

2. assuming i dont drain pool and deal with a CYA of 80, and i get FC up to 10, how long usually will that stay at 10 before i need to add more liquid chlorine? and i guess the idea when it goes down, i just need to add back enough liquid chlorine to get it to the 9-11 range?

Generally, the FC loss per day is somewhere between 1-4ppm. Higher side at the peak of summer, lower side in off-season. But I suspect with this algae lurking, the loss. Will be rather higher than lower. You need to follow me out with testing how much you lose per day and adjust your testing and chlorine addition scheme accordingly.

 

[Mdragger88]

To help clear a little bit up-
The yellow “daily” test with the comparator block is the OTO test
This only measures Total Chlorine up to 5ppm - its more of a quick check “do i have any chlorine or not?” Kinda test - not super accurate.
Fc (free chlorine)
+
CC (combined chlorine)
= TC (total chlorine)
You need to know fc & cc separately so use the fas/dpd test (the one with the powder).