Taking over pool care

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Wulfdan

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Jul 23, 2018
87
Crawfordville FL
Hello all, first time poster here, though I’ve read many posts looking for answers.

all pool information is in my signature.

current test results:
[FONT=&quot][FONT=&quot]FC 14ppm[/FONT][/FONT]
[FONT=&quot][FONT=&quot]CC 2.4[/FONT][/FONT]
[FONT=&quot][FONT=&quot]pH 7.6[/FONT][/FONT]
[FONT=&quot][FONT=&quot]TA 130ppm[/FONT][/FONT]
[FONT=&quot][FONT=&quot]CH 250ppm[/FONT][/FONT]
[FONT=&quot][FONT=&quot]CYA 85-95ppm

water is clear. Currently chlorinated with automatic feeder using tablets. I want to switch to the BBB method.

i know I need to replace water to get the CYA down. I’ve turned the chlorine feeder off for the moment to see how much the sun can bring it down tomorrow.

What else should I be planning on doing?


[/FONT][/FONT]
 
You basically just need about a 50% drain and refill and then perform a SLAM to get your water chemistry on point. Your CC's are high, which means there's a good chance that something is growing in your water even though it still looks clear. Like you said, turn off the tablet chlorinator, remove the tablets and don't use anything from now on except liquid chlorine. Everything else will add CYA to your pool with every dosage.

You've already got a good head start with a good test kit. And, of course, avoid the pool store and don't let them sell you any chemicals. Once you've got your cya down and the pool refilled and balanced, you'll pretty much be adding only liquid chlorine and a little muriatic acid to lower the pH occasionally.
 
Wulfdan said:
CYA 85-95ppm
Click to expand...

There is no such thing as CYA 85-95. CYA tube markings are logarithmic, not linear and you cannot eyeball values in between the markings. Halfway between two markings is not 5 difference, For that reason you always round up. So your CYA is 90 - 100.

With that high a CYA you need to follow step 8 in Pool School - CYA testing directions.

8. If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:
Fill the mixing bottle to the lower mark with pool water.
Continue filling the mixing bottle to the upper mark with tap water.
Shake briefly to mix.
Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
Continue the test normally from step 2, but multiply the final result by two.
Click to expand...

That will give you a better indication of how much you need to drain your pool. Since you need to do the SLAM Process process you should get your CYA down around 30. That is a drain of 2/3 of your pool. With a vinyl pool it is best to do that using the water exchange method. Marty should be by here soon and give you the details how to do that.

Once you get your CYA down to 30 follow the SLAM Process process and use liquid chlorine/bleach to raise your FC up to 12 based on [FC/CYA][/FC/CYA]
 
With at least a 50% reduction in CYA needed and vinyl liner pool you will need to do two drain/refills or you can do one exchange.

If you would rather drain/refill, you can drain down to leaving 1 foot of water in the shallow end. Then refill, circulate, retest your CYA, and do again.

Or

You can exchange some water without draining.

If you place a low volume sub pump in the deep end and pull water from there while adding water in the shallow end (through a skimmer or into a bucket on a step so you lessen the water disturbance) you can do a fairly efficient exchange. That is assuming the water you are filling with is the same temperature or warmer than your pool water. If your fill water is much cooler than your pool water, then switch it. Add the water to the deep end (hose on bottom) and pull water from the top step.

The location of the pump and fill hose may change if you have salt water, high calcium, etc.
In my pool, with saltwater and high calcium when I drain, I put the pump in the deep end and hose in shallow end. The water in the pool weighs more per unit volume than the fill water from the hose.

Be sure to balance the water out and water in so the pool level stays the same. Also be sure your pool pump is disabled during this process. Once started do not stop until you have exchanged the amount of water you wish.
 
I will retest CYA in the morning and post here. I need to get the CYA and FC into reasonable ranges and then I’ll retest everything.

i have no deep end to perform a water exchange. Pool is a 4ft deep circle. Darn tablets are more trouble than they’re worth
 
An above ground pool, sorry I did not catch that.

You can drain down to leaving 1 foot of water in the pool. So no issue doing a conventional drain refill.
 
Hit a little snag, I can’t do the drain and fill right away as the queen has decreed no. She doesn’t like cold water. To her anything below 86 is cold but I digress...

should i I just add bleach to maintain FC at a level appropriate for my high CYA until I can dump most of the water and refill?
 
With CYA 100 you have a target FC level of 11-13.

Note that with a FC level over 10 it is difficult getting a good PH test.
 
Welcome to TFP Wulfdan...

You have come to the right place for assistance and the folks already responding have you covered. They will reply about not draining soon...
 

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This morning’s test results

FC 14.5ppm
CC 0
TA 130
CH 230
CYA 140
temp 84F

The increase in free chlorine I think is from the tablet feeder still being on slightly. I didn’t have it all the way to the off position. That has been corrected.

CC of 0 I think is legit because I did the chlorine tests much faster this morning, yesterday I think I let it sit too long between steps

i also read the pH a couple seconds after mixing so I think that’s a reasonable result

did the dilution test for CYA and the dot disappeared between the 60 and 70 markings, so I rounded up.

so with a CYA of 140 I need to add some more liquid chlorine?

EDIT

added 73oz liquid bleach 6% to bring chlorine to 17ppm as suggested by pool math app.

second EDIT

I’m taking care of this pool for my parents, and my mother insists they’ve never had to change the water more than once a season (they’ve always used a tablet feeder). So eventually they’d get algae bloom they couldn’t control because the CYA was super high. And they’d shock it with dichlor so...

anyway, she’s not wanting to drain any water, or hear that the way they’ve been handling the pool for years is wrong so this leaves me in a bind. I’m in north Florida so I’m hoping that by keeping the FC at the high end of recommended combined with the sun and high water temp the CYA will come down somewhat quickly.

I might have to change the water on the sly, we will see...
 
You know your situation and what you need to do. Good luck!
 
Ok so the parents have decided that they don’t want to drain and fill unless it turns green again.
CYA is still 140
Per PoolMath I will bring FC up to 17ppm each morning with bleach.
The plan is to allow the CYA to fall naturally through UV, water temp and high FC. Along with backwashing and water replacement via rain or tap water.

Does anyone see a major problem with this plan? I know it’s not ideal.
 
When you test in the AM every few days check your pH. Add the drops and look at it quickly.

Otherwise, good luck.
 
One more quick question.

i am sourcing concentrated liquid chlorine and found that my local Ace hardware does refills of 2.5 ga 10.5% for 5.29

poolmath says this works out to .16/oz liquid chlorine. Is this a good price or should I shop around some more?

they also have gallon jugs of 20 baume MA for 8.99. That seems sorta expensive to me but it’s the first time I’ve purchased MA so...

thanks
 
Last edited:
The chlorine is a really good price. Are you sure it is 10.5% and not 12.5%? 10.5% is an odd concentration.

The MA is a bit expensive. Check Home Depot or Lowes. Normally have 2 pack of 31.45% for around $12-$13.
 
Wulfdan said:
Ok so the parents have decided that they don’t want to drain and fill unless it turns green again.
CYA is still 140
Per PoolMath I will bring FC up to 17ppm each morning with bleach.
The plan is to allow the CYA to fall naturally through UV, water temp and high FC. Along with backwashing and water replacement via rain or tap water.

Does anyone see a major problem with this plan? I know it’s not ideal.
Click to expand...

I mean, one major problem is that UV, water temp, and high FC won't do anything to the CYA. The only way to get rid of CYA is to get rid of the water that it's in.

Backwashing will (slowly, for some people, very, very slowly) exchange water, but it will be very inefficient and could take a very, very long time).

Maybe just the next time it's raining (it's Florida, so this afternoon I assume) go drain as much as you can, it'll blend in with the rain water, and you can tell them they had a big leak but you fixed it. Fill with hose. Repeat as necessary. (Kidding, sort of)
 
kchinger said:
I mean, one major problem is that UV, water temp, and high FC won't do anything to the CYA. The only way to get rid of CYA is to get rid of the water that it's in.
Click to expand...

Not true. Water temperature and high FC does degrade CYA. Not quickly. But over time you can see 5-10 ppm loss per month if your water temperatures are high enough. Elevated FC increases that.

Degradation of Cyanuric Acid (CYA))

Spas/hot tubs see rapid degradation of CYA levels due to hot water.

Take care.
 

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