Drain and Refill Chem Help

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T

trickle

0
Jun 3, 2018
16
San Diego, CA
Hello,

I just finished two 45% pool drains and refills. Est 32k-34K gallon free form pool. I could use some of the great TFP wisdom in getting the chem back to where it should be.

These are the chems I have on hand:
4 Gals 10% Sodium Hypochlorate,
2 gallons 31.45% Muriatic Acid,
5 Lbs Cyanuric Acid crystals, (need twice that much?)
5 Lbs Sodium Bysulfate granules,
4 Lbs 20 Mule Team Borax,
12 Lbs baking Soda (Arm and Hammer), and
6 Lbs Sodium Carbonate granules,
a couple nylon stockings and a
5 gallon bucket and the
Taylor K-2006 (FAS-DPD chlorine) test kit.

With City 200 ppm CH, and home softener CH 70ppm combined, I got the CH down from 1050. These are all my numbers immediately after water refill this morning, and what I think I should have for goals. Since this is my first attempt at balancing, my part of the wisdom will be to lean on the TFP wisdom for the proper sequence of additions for the water treatment:

Time: 5/19/21 (9:00 AM)
CH 335, (goal same?)
CYA <30, too low for the Taylor test to satisfy, (goal 40?)
FC 0 (goal 4)
TA 120 (goal 80?)
pH 8.0 (goal 7.4?)

Thanks in advance for the assist. Would like to thank the pool guy for his services too, as soon as possible.
 
You need the liquid chlorine, the muriatic acid, and the stabilizer. The rest of the chemicals are not needed. Now or ever if you follow TFPC.

Add 10 ppm CYA worth of stabilizer.
Add liquid chlorine to get FC to target level for 40 ppm CYA. See FC/CYA Levels
Add acid to lower pH to 7.4,.
 
I've finally got it clear in my head that, to begin, I need to first drop the pH to 7.0-7.1 (Mur Acid), to address the TA properly. Then I can go through all the levels and adjust; pH first, then CH, CYA, and finally FC. The CYA being granular, must I wait for 24 hrs+/- to proceed with any other adjustment? Can I do this in half measures, and then come back and repeat the process, one or more times, inching closer to where I need to be? I can see what needs adding, but the order is a bit confusing, as one adjustment moves another. Well.....that's progress. I'm now thinking about possibilities I had not considered before. You know? One does not know what one does not know. Ignorance was bliss when the pool guy did it. Not blissful right now, I'll tell ya.
 
First is always chlorine. Be sure your pool water has target level FC based on your CYA.

Start the CYA dissolving. Add the chlorine. Add the acid. Only need to wait 15 minutes between the chlorine and acid.
 
Thanks MkNauss. I very much appreciate your assistance. There were a dozen path I was considering taking and none were anywhere near as streamline as yours. Not sure, but somewhere in the process I may have accepted an incorrect value from a previous test run in the "Pool Math" and I would then have added chems accordingly. Whoops. Anyway, an hour after the fact, the test results appear to still be in the ballpark. The TA is unchanged and still high. I did the calc for a pool on the low end of what I estimate this free form pool to be. IE: 32000 in lieu of 34400 gals. Not much difference in chem requirements, but I thought it better to under estimate rather than over estimate. The Cyanuric acid value, I assume will increase, since the granules are no where near dissolved, in spite of my best effort in low quantities in a dozen 5 gal pails full of water. I raked them around the bottom as well, where some had gathered. If there 's a technique to dissolving the granules before dumping them in the pool, I missed it.
Anyway, I reached my arm in the pool to collect water and it came out undamaged, so the first test was successful. Here are the results of the other tests:

FC 5.6
CYA 34
CH 335
TA 120
pH 7.4
 
You use the sock method for CYA. Never put directly in your pool. It can stain your pool surface.

Solid/granular cyanuric acid (CYA) should be placed in a sock and the sock put in the skimmer basket or suspended in front of a pool return. After adding CYA you should leave the pump running for 24 hours and not backwash/clean the filter for a week. Squeezing the sock periodically will help it to dissolve faster. Test and dose chemicals in your pool assuming the amount of CYA added is in the pool according to Poolmath. CYA can be tested the day after it is fully dissolved from the sock.
 
Don't worry about your TA right now. You can adjust that last if you want. Your CH and pH are both fine. Get the FC in the pool right away so nothing begins to grow in the water. Adjust if necessary once you get all your CYA fully dissolved and fully mixed.

Then once you have everything else adjusted, you can adjust TA by adding muriatic acid to drop pH down to 7.0. The muriatic acid will drop both pH and TA and then you need to aerate the pool which will raise ONLY pH back up. It won't affect TA. Then just repeat the process until you get your TA where you want it. It's good to run pH, TA, and CH tests on your fill water so you know what you are working with. I see you have a water softener for topping up your pool. That will keep your CH from hardly moving for a while. If you just use the water softener, it will take an entire pool's worth of water additions for the CH to climb 70ppm or whatever your CH is coming from the water softener. I have a similar setup as well. I don't believe TA is affected by the water softener, so definitely run that test so you know how it will affect your top ups. Mine, unfortunately is TA 330:mad: which causes my TA to climb as I add water, so I have to add extra muriatic acid every once in a while and aerate to get it where I want it to be (70-80).
 
mknauss said:
You use the sock method for CYA. Never put directly in your pool. It can stain your pool surface.

Solid/granular cyanuric acid (CYA) should be placed in a sock and the sock put in the skimmer basket or suspended in front of a pool return. After adding CYA you should leave the pump running for 24 hours and not backwash/clean the filter for a week. Squeezing the sock periodically will help it to dissolve faster. Test and dose chemicals in your pool assuming the amount of CYA added is in the pool according to Poolmath. CYA can be tested the day after it is fully dissolved from the sock.
Click to expand...
Ugh! I know, I know. That darn sock. I had one and for one fleeting moment, I knew to use it but then forgot. The 2nd time I added the CYA (the day after), I did use that sock. I was much calmer then. I overthought the whole drain refill and chem balance process, and it was the ridiculously simple things that I overlooked. The Neanderthal is indeed strong in me. If I'd have hired me, I'd have fired me. I had the entire periodic table racing through my head, and I was trying to absorb all the possible ways I could treat the pool. If I'd have stayed in my lane and dealt with only what was in front of me at the time, I'd have been fine. I knew when I was treating the pool that I wasn't doing something right. It was ticking in the back of my head but I didn't find its way to the front until the next day.
 
DeanP66 said:
Don't worry about your TA right now. You can adjust that last if you want. Your CH and pH are both fine. Get the FC in the pool right away so nothing begins to grow in the water. Adjust if necessary once you get all your CYA fully dissolved and fully mixed.

Then once you have everything else adjusted, you can adjust TA by adding muriatic acid to drop pH down to 7.0. The muriatic acid will drop both pH and TA and then you need to aerate the pool which will raise ONLY pH back up. It won't affect TA. Then just repeat the process until you get your TA where you want it. It's good to run pH, TA, and CH tests on your fill water so you know what you are working with. I see you have a water softener for topping up your pool. That will keep your CH from hardly moving for a while. If you just use the water softener, it will take an entire pool's worth of water additions for the CH to climb 70ppm or whatever your CH is coming from the water softener. I have a similar setup as well. I don't believe TA is affected by the water softener, so definitely run that test so you know how it will affect your top ups. Mine, unfortunately is TA 330:mad: which causes my TA to climb as I add water, so I have to add extra muriatic acid every once in a while and aerate to get it where I want it to be (70-80).
Click to expand...
Thanks for the info. I am only a few days new to being hands on with pool balancing (scary), but I had not found any other practical way to address the higher TA, than the way you suggested. I have an attached spa that waterfalls into the pool, if I let it. The 4 or 5 jets do some very intense aeration in the spa. I understand that raising the pH this way does work, but it is a lengthy process. With this method, how long did it take you to raise the pH back up to where you wanted it? Days or weeks?

Fyi, The City water chemistry here is CH 200, TA 110, and pH must be about 7.4 since I just refilled most of the pool water which now has that pH. The softener pH is 8.0, TA 130, and the CH is also 70 ppm. I don't like the idea of running high volumes of water through the softener, but I certainly didn't like dumping two lifts of 14,600 gallons of water to get the CH down either. That's almost criminal down here in San Diego County where infrequent rain is typically measured in tenths of an inch, but fires in thousands of acres.
 

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In my 20k gallon pool, it usually takes me anywhere from 8 to 12 hours to bring the pH back up to around 7.5 from 7.0 with aeration. The more bubbles you can create, the faster the pH will rise. I built my own aerator that I use to attach to my pressure side fitting in the pool wall, but have since attached it to a submersible pump to save electricity and because I got rid of the booster pump for a robot. :)

I built this thing for under $20 with parts from Home Depot and it attaches to my submersible pump with a union whenever I need to aerate:





The second pic is the aerator attached to my submersible pump in the shallow end.
 
I like that submersible pump idea. 8-12 hrs for a .5 pH increase isn't too bad, if the required pump power consumption isn't too high. It's a simple no fuss pH adjustment. I still have my submersible out from draining the pool. Mine is 1/8HP 120v, 1268GPH. That level of flow through your jets looks very much like my attached spa, but it sounds like it's no where near the power consuming 2.5HP pump that feeds my spa. I'll see what I can put together to see what my submersible pump will do. I don't recognize those spray fittings. Is that a closely held patented process of yours, where you drilled out some end caps, or are those parts you purchased?
 
You are correct, I carefully drilled out end caps. :) I also put a T near the top of the vertical pipe so I could glue in another piece of pipe and an end cap on the pool deck to keep it from moving around all over the place. That planter that is cockeyed in pic 2 is holding down the pipe on the deck with its weight.
 
Thanks! I do have those technical components on hand. And, in the event you have not patented this yet, your secret is safe with me. I immediately recognized the pot for ballast technique. I think man discovered that use shortly after he invented the pot and filled it with dirt. I currently have several examples of that most useful function. Several have plants in them as well.
 
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