First time poster - Makin sure I'm on the right track :)

[Jake&Clan]

Hi all!

We live in southwest Ohio with four young kids (7,6,4,2). We have an above ground 24' pool 48" in depth. By my calculations that's around 13,000 gallons of water. Our temperatures during the summer are usually the low to mid 80's in June and flirt with the 90's in July. That is, until this year. We're camping low to high 90's all week and it'll repeat next week.

Last year we erected the above ground pool and it's new liner. I noticed that, throughout the summer, I was adding what I felt was a LOT of chlorine. 2-3 gallons every 1-2 days during the hottest parts of the summer. With every addition of chlorine I was (for the first 3/4 of the summer) adding in sodium Bisulfate (made by Clorox) because, without it, the PH liked to hover 7.8 - 8.0. Total Alkalinity on this pool (and every other smaller vinyl pool we've had) is high - 180+. On and on the cycle went. Tons of chlorine, tons of sodium Bisulfate, repeat. Additionally, I had conditiner in the pool all the way to the maximum amount of 100ppm (we're talking borderline 'I gotta drain some of the pool before this gets cloudy' kind of thing). ANYTHING to try and keep the chlorine from burning off so much.

At the VERY end of the summer I decided to rekindle my long lost tumultuous relationship with Muriatic Acid. I don't recall the results because it wasn't long before we shut the whole thing down for the fall/winter. Swim season lasts until about Labor Day. Until then, I had preferred the granualr sodium Bisulfate for the obvious reason of - MA is just no fun to play with. The goal was to lower the TA (something that, according to the pool store, 'happens naturally as the PH balances itself out.'). The pool store's comment wasn't entirely wrong. In years past, dealing with 2-3k gallon "Walmart Special" vinyl pools, the TA did seem to lower when PH consistently stayed normal. The issue, here, though is the PH goes out of balance every time I add chlorine.

At 12:00am on Thursday morning I added 2 gallons of chlorine to the pool. At 8am that same day it registered around 5ppm. I say "around' because I was in a rush and just a test strip vs my K2007 Taylor kit. A few hours later when my wife and kids hopped in she said it was "somewhere between 3-5ppm." By this morning, 0ppm. That's 2 gallons of chlorine gone in 32 hours. Yesterday (like the last 3 days) was pretty hot. 97, 92, 94 (Tuesday, Wednesdsay, Thursday). The pool sits in direct sunlight all day long. We do NOT cover it, ever, and the water temp is hovering around 87 degrees. 84 this morning but it's starting to cool off for the next couple days before spiking into the 90s again all week next week.

THE ENTIRE POINT of this post is to ask the following: Am I following the right trajectory with targeting the pool with a LOT more Muriatic Acid? The Taylor kit is suggesting that, to lower the TA by 100ppm (it was 180ppm this morning) a 10,000 gallon pool needs a gallon. We're at 13,000. Looks like I'm going to the pool store. While the sodium Bisulfate was effective in lowering PH it did nothing to the TA. Frankly, at the time (last year), I wasn't even caring about the TA. Now I'm beginning to read that the high TA/PH is likely a contributing factor to my chlorine issues.

This year my "crazy" idea (since liquid shock isn't a riot) was to rely on tablets. I have two 3" tablets in my floater and they're doing practically nothing. My HOPE was to go ENTIRELY to tablets for TFPC and just keep a VERY close eye on the CYA. I figured, considering the bag fulls of CYA I added last year that omitting this practice, and letting the CYA from the tablets be the CYA additive, that I'd gain both the lower maintenance of tablets plus the necessary CYA to help with burn off. I don't think that's working. The CYA is still very low (like 0) and the tablets aren't doing squat in terms of keeping the pool chlorinated. I just don't to get to that true TFPC point where PH is stable, chlorine is stable, but my CYA is at the upper end of its limits and I'm forced into using liquid shock when I'd rather TRY and maintain with the tablets.

I welcome and appreciate your advice. Be kind as this is my first post and only 2nd year managing a pool bigger than 2-3k gallons. Feel free to point out anything I'm doing incorrectly.

Thanks!

 

[Texas Splash]

Am I following the right trajectory with targeting the pool with a LOT more Muriatic Acid?

No, not really. An elevated TA can be a bit of a nuisance by allowing the pH to rise a bit faster than normal, but it's not critical to the overall chemistry. Here are some points:
1 - Use your Taylor K-2006C test kit if that's what you have. Or get a TF-100. But avoid test strips and the pool store unless you want to be more frustrated.
2 - Only use the muriatic acid when the pH hits 8.0. When it does, use enough acid to lower the pH to about 7.2. The PoolMath APP can help with dosage amounts. Each time you do that it will lower the TA a little at a time. Don't obsess about the TA. Focus on the pH.
3 - Keep your FC balanced to your current CYA as noted on the FC/CYA Levels.

That's it! Use only the products and advice noted in the Pool Care Basics and you should do very well. Hope that helps.

 

[Texas Splash]

Oh, and welcome to TFP!

 

[PieterS]

2 - Only use the muriatic acid when the pH hits 9.0

Hey @Texas Splash - did you really mean to say 9.0 or should that read 8.0?

 

[Jake&Clan]

No, not really. An elevated TA can be a bit of a nuisance by allowing the pH to rise a bit faster than normal, but it's not critical to the overall chemistry. Here are some points:
1 - Use your Taylor K-2006C test kit if that's what you have. Or get a TF-100. But avoid test strips and the pool store unless you want to be more frustrated.
2 - Only use the muriatic acid when the pH hits 8.0. When it does, use enough acid to lower the pH to about 7.2. The PoolMath APP can help with dosage amounts. Each time you do that it will lower the TA a little at a time. Don't obsess about the TA. Focus on the pH.
3 - Keep your FC balanced to your current CYA as noted on the FC/CYA Levels.

That's it! Use only the products and advice noted in the Pool Care Basics and you should do very well. Hope that helps.

I'm using a Taylor K2007 kit. Current PH is indeed at 8.0 and I haven't added any chlorine and there is none in there (chlorine). So that PH is gonna climb.

In years past I've only ever focused on the pH but the pH spikes every time I had chlorine. It just love to sit around 7.8, sometimes higher. I guess last year I just kept trying to get it settle at 7.4 but unless I add ph down EVERY time I add chlorine it wanted to settle at 7.8-8.0. After adding that 2 gallons of shock the other night it was at 8.0...So you're suggesting I continue to add chlorine and just keep throwing in Sodium Bisulfate if it's at 7.8ph?

 

[Texas Splash]

Hey @Texas Splash - did you really mean to say 9.0 or should that read 8.0?

That was a typo, but I fixed it a few minutes ago. It reads correctly on my end.

 

[Texas Splash]

Many pools tend to have a pH that settles around 7.8. Don't try to force it down unless you are lowering the TA. In your case, with a TA ~180, that sounds like a good plan. PH hits 8.0 and lower it to about 7.2. Once you get the TA down to about 60-70 that should help quite a bit. It will take time, just be patient and repeat the process. Yes, balance the FC to the CYA to avoid algae. You certainly don't want to add algae to your weekend "To-Do" listing. Chlorine has a minimal impact on pH unless the FC is over 10, then it begins to effect the pH reading.

 

[Jake&Clan]

Many pools tend to have a pH that settles around 7.8. Don't try to force it down unless you are lowering the TA. In your case, with a TA ~180, that sounds like a good plan. PH hits 8.0 and lower it to about 7.2. Once you get the TA down to about 60-70 that should help quite a bit. It will take time, just be patient and repeat the process. Yes, balance the FC to the CYA to avoid algae. You certainly don't want to add algae to your weekend "To-Do" listing. Chlorine has a minimal impact on pH unless the FC is over 10, then it begins to effect the pH reading.

Then something else is doing it. It'll be a Ph of 7.6, I'll add 2 gallons of chlorine, and within 20 mins ph reads 8.0. Can't figure out what else would do that so quickly and consistently

 

[mknauss]

I'm using a Taylor K2007 kit.

That is a Pool Inspector Test Kit. It does not have the tests needed for maintenance of pool.

Get a K2006C or TF100.

 

[Jake&Clan]

So 3 hours ago I used the app to calculate how much chlorine should I add. It told me to put in 67 oz of chlorine to get it to 4.0 FC. 10% bleach was my entry. I added in 72oz.

Tested 3.5 hours later.

Chlorine is 1.5ppm.

This is exactly what I'm talking about. Nowhere close to 4.0.

Apologize but I'm a little confused. I'm hearing don't use muriatic acid unless the pH is 9.0. The pH is at 8.0. However, total alkalinity is now 160-170 (wind blowing drips lol). I'm assuming the instruction about not using MA unless it was 9.0 would be if I wasn't trying to knock that down with it being so high, now?

I think I'm going to take you up on the advice about the test kit. The instructions stated that if I suspect high TA I can use the 10 mL in the comparator and essentially "halve" the amount of #7/8 re-gent before mixing in #9 to count the drips for color change. I did that twice. Said TA was 80. No way it dropped 100. I do it again only using the standard 25ml line with the normal 2/5 drops of #7-8 reagent. Now it's giving me 160.

Kit = Crud.

Still frustrated that the recommended dosage of chlorine did so little to the FC. I'm guessing I need to abandon my chlorine tablet plan and yet some CYA in here much quicker than a tablet is gonna go it?

 

[IceShadow]

See above - he meant to put 8.0. At 8.0 you want to add to bring it down to 7.2. Don't wait for 9.0. That's pretty basic.

Two things will eat up FC in most pools - algae/organics, and sun. You need a kit that can accurately measure FC - the comparator block just won't do, except to tell you if you have FC at all. Looks like the K-2007 only comes with the CYA, pH, and comparator block FC tests. It's missing the TA, CH, and FAS-DPD chlorine tests to give you that info.

I'd recommend replacing it with a K-2006c or a TF-100 kit (same chems, just in different qtys for those kits) and testing with that. Then we can do accurate FC testing, run an Overnight Chlorine Loss Test, and see if it's organics eating your FC or if you don't have anything growing and maybe you just need to bump your CYA.

The tablets aren't going to release FC in a fast enough fashion for you without also bumping your CYA up to where it doesn't want to be for a sanitary pool. Liquid chlorine is the thing to use. You're in Ohio, so you probably have Menards near you - they have pretty good pricing on 12.5% liquid chlorine there.

 

[Jake&Clan]

Gonna grab another kit. I can't even tell what the PH is in this photo. Really "dark'' orange. Take the 7.6 and make it much darker. It doesnt have any red in it. So not 7.8. Maybe 7.7? Made a stupid mistake and added 47oz of sodium bisulfate (was supposed to be 32 oz) when it was at 8.2 figured the Ph would be real low. But this is what I'm seeing. Also added in 2lb of CYA (math called for 4) and it's now at 35ppm

 

[IceShadow]

Until the kit is in it's hard to give advice. If your FC is actually sky-high it would explain the pH reading - if it's 10ppm or above it can bleach out the reagent and make it look darker red than it otherwise would.

I'd wait on the kit. If the pool is clear, I'd add 3ppm daily of FC via liquid chlorine until it's in. Once it's in, run a full suite of tests and we can dial in what we need to. If the water is hazy or any algae is apparent, I would instead add 5ppm daily of FC via liquid chlorine to keep that at bay while the kit is on its way.

 

[Jake&Clan]

There's not a bit of algae in the water. This morning it was at 8ppm FC. 8 or so. Gets hard to tell the difference between 8 and 10. I just bought a new comparator for the k2007 too (sucks since I bought the tf-100 today) to get a better view of the darkened down chlorine side (made seeing the black dot impossible for CYA).

 

[IceShadow]

I would try to maintain the FC around 5 or so until the test kit comes in. Then you can do the Overnight Chlorine Loss Test and confirm you're algae-free. Make sure the FC is under 10 when you do the pH test. If it is high (8.0 or higher), then add acid per PoolMath (you'll need to know the TA too, to know how much to add). You can re-test the pH after 30 minutes or so of mixing to verify it dropped where you wanted. If anything, aim a little low with your addition. You can always add some more acid. Correcting it back higher if you add too much would mean more chems (or aerating to allow the pH to raise if it's not TOO low).

 

[jeffchap]

Forget about chasing TA. I haven't measured it in years. Use MA to keep pH between 7.2 and 7.8 and give it no further thought. It's just not that important, especially with a vinyl pool and no heater.

Add CYA to achieve 30 ppm and then dose only liquid chlorine daily to keep FC between 3-5 ppm and that's all you need to worry about.

Bottom line:

Raise CYA to 30
Check FC daily and add back to 3 - 5 with LC
Check pH weekly and bring to 7.2 - 7.8 with MA

 

[Jake&Clan]

The TF-100 arrived but I'm a bit confused why I have it now compared to the k-2007 I had. The chlorine and ph test is just a k-1000 from Taylor that is less accurate (pH goes up in 0.3ppm thresholds) than my 2007. Thankfully I did buy the test meter.

 

[jeffchap]

I don't think the K-2007 has a FAS-DPD test, does it? That's what you were missing. Without that, there's no way to measure FC above 10 ppm.

 

[duraleigh]

Jake and Clan,

I had to look up the K-2007 to see what it was! It does not contain the all important FAS/DPD test which allows you to measure FC well above 10 ppm. This is a pricey test but mandatory for the methods we teach.
It has no CC's test
It also has no TA test
It also has no CH test

The Phenol Red pH test (that is in both the K-2007 and the TF-100) is the most dependable pH test at a reasonable price. A digital tester can be had for quite a bit more money (I see you already purchased it) but you really can trust the Phenol Red pH test.......inexpensive and remarkably dependable

 

[Jake&Clan]

I don't think the K-2007 has a FAS-DPD test, does it? That's what you were missing. Without that, there's no way to measure FC above 10 ppm.

FAS-DPD... is that the chlorine drop test? Instructions in the tf-100 say it measures chlorine drop, calcium hardness, Ta, CYA, and pH/ chlorine using the comparator block.

On that note, the chlorine drop test says out a "scoop" of R-0870 in. This the scoop it's talking about?