"Go ahead and use 2 chlorine tab floaters," said the Pool Store.

Sun_Devil_Mike

New member
Jul 5, 2019
4
Tempe, AZ
I am a first-time poster here on TFP and a relatively new pool owner (less than 2 years). I emptied the 20K-gal IG plaster pool completely in March of last year and have been able to coast for a good while on that. At some point between then and now, the Pool Store suggested a second floater to keep chlorine up, and up until recently I had been living blissfully ignorant, dropping tab after tab of trichlor (thanks, jblizzle) into them. And now here I am.

Approximately 8 days ago I noticed slight change in color of the water (a hint of green) towards the end of the day. Multiple pool stores said everything looks fine. I order a test kit (wrong one, don't know it yet). I start researching and find TFP. I read Pool School articles and try to learn my ABCs. I remove tabs and switch to liquid chlorine. I order another test kit (Taylor K-2006). About 3-4 days ago the water began turning more teal and cloudy. The bottom of the deep end was always visible, but things were trending in the wrong direction. My test kit had not arrived yet but I figured from reading on here my CYA levels were likely through the roof and I would need to add a good bit of liquid chlorine. That's what I did: 4.5 gal of 10% evening of 7/4, additional 1 gal of 10% evening of 7/5, no chlorine added evening of 7/6.

Current situation: This morning the pool is clear, as good as it has looked in more than a week and a half. The color is good, too, quite blue (maybe the faintest hint of teal depending on the angle). My Taylor test kit arrived last night. Here are my numbers (this is my first attempt with this test kit):

FC - 28 (holding steady from my first FC test attempt from prior evening)
CC - 0.5-1 (was almost clear after 1 drop)
pH - 7.6
TA - 150
CH - 575
CYA - well off the readable range (100+) on Taylor K-2006

From what I have read here, my CYA is too high for SLAM. A drain/refill would be the next step. But I'm in Phoenix with a plaster pool and now is not the time for a drain. I have seen the suggestion to exchange water with a low-volume pump, perhaps by filling from one end of the pool while draining from the other. I'm game to try that if that is my best way forward.

I am grateful that I found this site and have been amazed by how generous users are with their knowledge. Thanks in advance for any advice/guidance.
 
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jblizzle

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May 19, 2010
43,260
Tucson, AZ
:wave: Welcome to TFP!

First a correction. The tablets are trichlor, not dichlor ;) but they both do add CYA.

You can do the diluted CYA to get a better feel for actual level. Start with a 50/50 mix of pool and tap water, then the reagent and double the reading.

Certainly going to have to do the simultaneous drain and fill method. You can get cheap submersibles at harbor freight. That is the best first step before following the SLAM process.
 

Sun_Devil_Mike

New member
Jul 5, 2019
4
Tempe, AZ
Thanks, jblizzle, for the welcome and advice. I attempted a diluted CYA test and would say it puts my CYA solidly above 200. Yikes. I can already tell that I will be burning through the CYA test kit reagent pretty fast while I try to keep track of my attempts to drive that number down. I will look into ordering more now.

I will be getting a submersible pump today and will start the water exchange process. I'm not sure how long it may take, considering I will only be exchanging water when I'm home and can monitor (evenings/weekends). My goal will be frequent testing to try and maintain FC enough to keep the pool clear throughout this process. I am using 10% liquid chlorine. I will update as I go. If anyone else has any advice on maintaining during the exchange process I'm all ears. Thanks!
 
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mknauss

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TFP Expert
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May 3, 2014
22,422
Laughlin, NV
You can exchange some water without draining. Do not stop the process until you have exchanged the amount of water you want. Most sump pumps will have a rate of about 7 gpm if you are sending the effluent through a garden hose. You can measure the rate by timing the filling of a 5 gallon bucket.

It will take a long time to exchange your water. If you start and stop like you say, it will take far more water to accompolish your goal,

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.
 
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jblizzle

Mod Squad
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May 19, 2010
43,260
Tucson, AZ
Follow Marty's process. You want to do the exchange without mixing the water or the process will be much slower.

Order refills for the FAS-DPD chlorine test and the CYA test. Both are lacking in the K2006. Tftestkits.net sells what you need.
 

kimkats

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Jul 10, 2012
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Tallahassee, FL

Arizonarob

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Mar 25, 2018
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Chandler Arizona
Hi neighbor, welcome to TFP!!

So, Mike Mike Mike Mike Mike, guess what day it is, guess what day it is? (Sorry couldn’t resist)
Today is the day you dump the pool store! (10 bucks says I can guess which one it is.)

Some good news for ya, monsoon is coming, and the sun is strong. Some free water, and oxidation of the CYA from the sun. That and your water exchange, you should be in good shape before you know it! :cheers:
 
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Flying Tivo

Well-known member
Jan 24, 2017
1,108
Monterrey, NL, Mexico
You can save some reagent by doing the 5ml samples, follow the extended direction for testing. You dont have to do frequent CYA testings, do the math on fill rate and go for it. It would be close to 85% drain/refill, but test after that. You did't post CH levels but for arizona it would probably be high.
 

Sun_Devil_Mike

New member
Jul 5, 2019
4
Tempe, AZ
You know it, Arizonarob! The silver lining to this episode is seeing the Pool Store clearly for what it is and breaking free from the cycle. (Local pool store in this case that was recommended by multiple people, not a national chain)

Once I can break free from a work issue, I will be obtaining a pump and starting the water exchange process. I will test the temperature of the water from the hose first. Our water is pretty dang warm right now so I am curious to see which is warmer and I will follow Marty's instructions for the water exchange based on what I find.

The pool currently looks good and has high FC. I have been running the pump almost 24/7 since issues got hairy about 4 days ago. I will stop the pump for the duration of the water exchange process and hope things stay clear. If the pump drains 7 gpm a 24 hour drain should be around 50% of my pool. I will measure the pump rate and the rate of output from my hose to see how often I'll have to stagger one or the other. Sounds like I might need to drain more than half though ... man.
 

Arizonarob

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Mar 25, 2018
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Chandler Arizona
CH is very high. I tested a 10 ml sample and it for it to turn blue and not just clear was 23 drops. CH = 575.
That’s not bad at all Mike. Mine is currently at 300, but my autofill is plumbed with softened water.
The fill water will definitely be cooler then your pool water, so you may have to pull from the top, and drop the hose in the deep end.