# Thread: Recuperating from a green pool

1. ## Recuperating from a green pool

Greetings,

The TF-100 kit arrived yesterday yea!

The pool was green last week, but without the kit it was not possible to know what to do. I studied the SLAMing article and decided to pour a gallon of chlorine every hour; it took two days for the green to turn milky.

Now, I vacuum and brush daily. I was afraid it may start going green, so I poured a gallon of chlorine once a day, till the kit arrived.

Here are the Test Results:

FC = 50
CC = 0
pH = 7.6
TA = 200
CH = 500
CYA = 100

Before I came to know about Trouble Free Pool I followed the 24 page booklet by Aquachek using their test strips. I used chlorine pucks in two floaters and poured PoolPerfect+PhosFree two cups a week. No green pool for about five years. Then suddenly a green swamp.

My questions:
1. I think I should stop pouring a gallon of chlorine daily as FC now is 50. But what FC should I aim for? The Calculator says Goal: 8 to 13. The Target column says 8.
What FC should I keep the pool at?

2. Is the pH of 7.6 ok?

3. TA is confusing. Do I bring it down by lowering pH?

4. CH When I put 500 in the Now column of the calculator with the Goal set at 350 the calculator says to replace 30% of the water with new water of CH 0. But my city water has a CH of 140 (I did the test).

5. CYA is 100 do I need to bring it down? I can monitor FC according to the Chlorine/CYA chart. Otherwise, the calculator says I have to replace 50% of the water—a shock to me!

Thank you,
Best wishes,
Swami

2. ## Re: Recuperating from a green pool

Welcome to TFP!!!

1. STOP blindly adding chlorine. Luckily your CYA is VERY high, so your FC did not get way too high. First you need to verify your true CYA level. RE-do the test with a 50/50 mix of pool and tap water, then add the reagent, then double the reading. Should be done outside with back to the sun and tube at waist level. And you can pour back and forth to see if you get the same thing.

2. The pH test is wrong when FC > 10ppm. Ideally you adjust the pH BEFORE you raise the FC level. The higher the FC, the pH will read inaccurately high.

3. Ignore TA for now When you add acid to lower pH, it will also slowly lower the TA.

4. Only way to lower the CH is to replace water, but yours is not extremely high enough to warrant that .... but ...

5. YES. You need to determine a better estimate of the CYA and then replace a lot of water to get back in the 30-50ppm range. You can thank your massive use of pucks for this. This should be your first step.

3. ## Re: Recuperating from a green pool

My first suggestion is to test the CYA again, but this time use 1/4 R-0013, 1/4 tap water, then 1/2 pool water. Or, you can dilute the pool water 50/50 with tap water before adding to your squeeze bottle. Test the CYA, then double the result. My fear is you are well over 100. Yes, it needs to be brought down, a lot. Down to the 30-40 range. You will be replacing MORE than 50% of your water.

Here is how to lower TA:
pool-school/lowering%20total%20alkalinity

CH will lower some when you replace water. The fill water of 140 will eventually drive it back up, but also using any CalHypo shock products will rapidly drive CH up.

Most likely the reason your pool suddenly became a swamp is the use of those trichlor tablets finally took [s:2dee7qpj]CH[/s:2dee7qpj] CYA so high that the chlorine was no longer effective.

4. ## Re: Recuperating from a green pool

I re-did the test four times with a 50/50 mix of pool and tap water, then add the reagent, then double the readings, which are:
120
140
120
120

What do these mean, and what do I do next.

Swami.

5. ## Re: Recuperating from a green pool

It looks like you tried the test 4 times, correct? So I'd say your CYA is more near 120 than 100. This is your first important piece of information - we are going to recommend you drain and refill to get that down to the 30-40 (or 50) range, preferably before you go any further. Performing the SLAM process with CYA that high is going to require a LOT of bleach.

6. ## Re: Recuperating from a green pool

What do these mean, and what do I do next.
read "The ABC's of Pool Water Chemistry" up in Pool School.

Then, read "SLAM - Shock Level And Maintain" in the How To section.

You must gain the knowledge that Pool School will give you. The TF-100 can only measure your chemistry.....it cannot tell you what to do about it. Learning what the parameters mean will give the start you need to make use of the kit.

7. ## Re: Recuperating from a green pool

I drained 60% of the pool today. Now, refilling has started. When the pool is filled, I'll do the tests and report. Might be a few days.
Thanks,
Swami

8. ## Re: Recuperating from a green pool

Hello,

The pool is refilled with 60% fresh water, here are the test results:

FC = 16
CC = 0
pH = 7.3
TA = 150
CH = 320
CYA = 50

What is the first adjustment to do when the pool was refilled?

What would be the second adjustment?

Thanks,
Swami

9. ## Re: Recuperating from a green pool

CYA of 50 is a good target. CH of 320 is just fine as well. Congrats!

Now you just need to follow the SLAM process and get your pool clear!

10. ## Re: Recuperating from a green pool

Do I need to SLAM. The pool is not green. The water is clear, except there is a lot of white powdery stuff on the bottom. I am vacuuming and backwashing daily.

11. ## Re: Recuperating from a green pool

You can determine if you need to by performing the OCLT. If you still have live organics in the pool, you will. This is how you find out.
pool-school/overnight_fc_test

12. ## Re: Recuperating from a green pool

Originally Posted by Swami
Do I need to SLAM. The pool is not green. The water is clear, except there is a lot of white powdery stuff on the bottom. I am vacuuming and backwashing daily.
As Robbie mentioned, the OCLT will tell if you have live organics in the pool. Now on the backwashing daily, we suggest that you only backwash when the pressure rises about 25% above clean psi read.

If any powdery stuff is still there after vac'ing, brush it up into suspension and let the filter handle it.

13. ## Re: Recuperating from a green pool

Hi,

For the last two days the pool has passed the OCLT, it is zero.

Here are the all the test results:

FC=9 (goes down by 2 every day. Since CY is 50 shall I keep it between 4 and 6)
CC=0
pH=7.6 (no one has used the pool to swim in the last 25 years)
TA=140 (pH & TA relationship is confusing. Help, what should I do)
CH=330
CY=50
Temperature of pool 73 degrees.

14. ## Re: Recuperating from a green pool

You can ignore the TA if you don't have pH rising all the time. If you do, just lower the pH to 7.2, let it come up, lower to 7.2 again... over time the TA will go down from this process.

15. ## Re: Recuperating from a green pool

Thanks Robbie for all your help.
Best wishes,
Swami

16. ## Re: Recuperating from a green pool

Originally Posted by Swami
Hi,

FC=9 (goes down by 2 every day. Since CY is 50 shall I keep it between 4 and 6)
One of the things that I have noticed from pool school is that if the minimum target is 4 and the target is 6 and you are losing about 2 ppm a day, some people would target 8 so that you have more room for error. So losing 2 ppm a day you would fluctuate between 6 and 8. It just gives you a little more room for error.

17. ## Re: Recuperating from a green pool

Yes, sounds logical, thanks.

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