Just got TF-100 Kit and here are my results. Please advise on what i need to add/do to change my levels

[StephenRMcKay]

Hey guys,

My TF-100 finally came, and I just took my first reading of the pool. The current levels are
FC 4
PH 7.5
TA 140
CH 140
CYA 100
I have a 30000 Gallon in ground pool. Please tell me what I need to do to lower my TA & CYA.

I go ahead and add some Bleach to bring up my FC.
Thanks in Advance

 

[mknauss]

Do the cya test again using one part pool water to one part tap water, then use that for your water sample. Double the result from that test.

 

[ajw22]

With CYA 100 you need to do the dilution test to see how high it really is...

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
5. Continue the test normally from adding R-0013, but multiply the final result by two.

Your TA is not a problem. Your CYA is. To lower your CYA you will need to drain 50% or more of the pool.

How do you intend to chlorinate the pool going forward?

 

[StephenRMcKay]

With CYA 100 you need to do the dilution test to see how high it really is...

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark with pool water.
2. Continue filling the mixing bottle to the upper mark with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
5. Continue the test normally from adding R-0013, but multiply the final result by two.

Your TA is not a problem. Your CYA is. To lower your CYA you will need to drain 50% or more of the pool.

How do you intend to chlorinate the pool going forward?

Ok I just did that test. The CYA reading level is 55. So doubling that I am at 110. That's even worse than 100. Please advise. Should I drain my pool to half?

 

[ajw22]

Not a big difference between CYA 100 and 110.

How do you intend to chlorinate the pool going forward? That will determine what CYA level you need to get down to.

 

[ajw22]

It is not safe to drain a vinyl pool that much.

Read about our No Drain Water Exchange process in Draining - Further Reading

 

[StephenRMcKay]

Not a big difference between CYA 100 and 110.

How do you intend to chlorinate the pool going forward? That will determine what CYA level you need to get down to.

My plan was liquid chlorine. My local lowes had it in cases of 6 gallon jugs for 4.38 10% chlorine. I bought everything they had and put it all in to kill the algae. I found some bleach with 7.55% chlorine here at my grocery store for pretty cheap. I'm going to call my pool store and see if they sell liquid chlorine by the gallon. but that's my plan moving forward. I'll check out your no drain article for vinyl pools. Thanks!

 

[StephenRMcKay]

Also, I just read the water replacement method. All sounds good, that's a great way to replace water without lowering the actual water level. My only question is how to determine TDS?

 

[ajw22]

Using Liquid Chlorine you should target a CYA around 40. That will require about a 70% drain.

@mknauss should be by soon to take you through the details of the no drain process

 

[StephenRMcKay]

Thanks ajw22!

 

[mknauss]

Also, I just read the water replacement method. All sounds good, that's a great way to replace water without lowering the actual water level. My only question is how to determine TDS?

Take a water sample to a pool store. They love to give TDS as part of their results. The bulk of the TDS will be calcium and salt.

The TDS of your fill water will primarily be calcium. You can test it for that.

 

[StephenRMcKay]

Take a water sample to a pool store. They love to give TDS as part of their results. The bulk of the TDS will be calcium and salt.

The TDS of your fill water will primarily be calcium. You can test it for that.

I'll take a sample to them in the am. Once I determine the TDS of my pool water, and fill water, how do I determine how much to replace?

 

[PoolStored]

I will predict that the TDS will not overcome the temperature difference of the water.

Given you are in TN, I predict you should add to the deep end (deep) and take water from the shallow. Will be interesting to see what your calculation result is...

I did a 5 gallon bucket test. How long to fill from hose. I attached 100' hose to a sump pump, and put a ball valve on the end. I then adjusted the outflow to match my inflow (sump was WAY stronger than input hose). It was pretty close. I just made minor adjustments to the ball valve after a couple hours and watched the pool level (put electrical tape on the skimmer frame to have a reference). Then I let 'er go. Based on the bucket test, I was within 1/2 hour of my predicted duration.

Easy to do. Go for it!

 

[PoolStored]

I'll take a sample to them in the am. Once I determine the TDS of my pool water, and fill water, how do I determine how much to replace?

CYA determines how much you should drain ...about 70%

TDS and pool and input water temperature determines where to add and where to drain.

Read this: Draining

See the section titled:

Pump from the deep end or near the surface?​

 

[PoolStored]

For how long to run, take the results of your bucket test (how many gallons per minute). Then take your pool volume x .7 and divide that by gallons per minute to determine how many minutes you need to run. Divide by 60 to get hours to exchange duration in hours.

 

[PoolStored]

The point of the calculation exercise is to keep the input water from mixing with the high CYA water you are removing.

 

[wireform]

The bigger the delta t the better the no drain exchange is. Time the hose very well to be sure you have the calculation to know how many hours it'll take to exchange X amount of water. Expect a few days and no swimming and no filter running for the duration of this process.

 

[StephenRMcKay]

Thanks so much guys. I'll get to it first thing in the am! Quick question. I am going to close the pool here towards the end of September. Is this worth doing now? Will my FC and TA and CH be out of whack when this process is done? Will I have to spend a small fortune in chlorine etc only to close it?

 

[PoolStored]

The bigger the delta t the better the no drain exchange is. Time the hose very well to be sure you have the calculation to know how many hours it'll take to exchange X amount of water. Expect a few days and no swimming and no filter running for the duration of this process.

Also, best not to stop the exchange to swim. If you do, will require more time/exchange because you mixed it.

I have 31K gallon pool, input max was about 5.5 gallons per minute, 40% exchange took me about 40 hours.

Typical hose is about 6 GPM. For a 70% exchange will take you about 58 hours.

 

[PoolStored]

Thanks so much guys. I'll get to it first thing in the am! Quick question. I am going to close the pool here towards the end of September. Is this worth doing now? Will my FC and TA and CH be out of whack when this process is done? Will I have to spend a small fortune in chlorine etc only to close it?

Yes, do it now. The lower CYA will require a lower SLAM level of FC when you close and protect the pool from opening green.

You can get all the chems in order before the close. Plenty of time.