TA and Chlorine go...up?

[Grubby]

Hey folks!

Thanks in advance for all the awesome support - this community is awesome.

First, here's a link to my pool's info. (My real-life nickname is Grubby, thus the silly pool name)

Tl;dr:

TA *increased* after adding MA and SLAM levels of chlorine. Total chlorine seems to have gone up over-night after starting the SLAM process. Is something weird going on? Do I not understand TA and/or chlorine counts? PEBKAC error? Also, when reading the label on Bleach, should I read the Sodium Hypochlorite active ingredient percentage (7.5% in this case), or the "Yields 7.1% available chlorine" note at the bottom of the label?

Narrative:

My new TF-Pro *Salt (with magnetic stirrer, which is pure magic) showed up (finally!) and I took some readings yesterday. My pool is nice and clear (or so I thought...), and it was late afternoon here in Las Vegas in full sunlight, but I couldn't resist taking some measurements. I was so excited!

FC - 0
CC - 0
pH - 7.5
TA - 120
CH - 250
CYA - 60
NaCl - 400 (my SWCG isn't active, just wanted to know what was in the water right now as a baseline for when I move to get it up and running)

Looks like after a busy weekend in the pool, my usual Tri-chlor pucks (pool-guy recommended) just didn't keep up. So....a SLAMming we shall go!

I filled my pool to the correct level (lost about 3" over the weekend), and took my next set of readings. I'm new to this, so wasn't sure by how much things would change with topping off the pool and measuring after sunset. Results:

FC - 0
CC - 0
pH - 7.5
TA - 120
CH - 275
CYA - 60

So...first lesson learned, even 3" in a 15kgal pool doesn't really move things very much. I assume that the Calcium Hardness change is actually a PEBKAC error.

Armed with my test results, I started the SLAM process by turning the pump all the way up and dropping my pH to 7.2 by adding 32oz of 29% Muriatic Acid that the previous owner left behind. Jeebus. That stuff is no joke. I didn't research much about *safe* ways to add it to the pool. So, I started by pouring from about shoulder-height from the measurement bucket. Thank Thor I didn't get splashed on. I was down-wind, and so got hit with a big whiff of gas. I immediately stopped what I was doing, got fresh air, and then pulled up TFP and researched how to *safely* add MA. My experience was much better after that.

After letting the pool agitate for about 15 minutes, I took a reading to confirm my pH had shifted to 7.2 (which it did, exactly. Thank you Pool Math app!) Next step was to bring the pool up to SLAM chlorine levels. First things first, I learned my lesson with the MA - and so I pulled up TFP and looked up how to safely add liquid chlorine (bleach) to the pool: pour slowly in front of a return in the deep end, about 2mins pour time per gallon. Got it! So, again, many thanks to Pool Math, (cross-referenced with the CYA/Chlorine chart here to extra assuredness) I added 626oz of Bleach, which was supposed to bring my FC count up to 24ppm, but here's what I got (full battery of measurements just to practice again with the kit, especially the CYA process, which feels weird still):

FC - 26
CC - 0.5
TA - 160
CH - 400
CYA - 60

Here's where my first questions come up. I added MA to drop my pH, which should have also dropped my TA, as I understand it. Do high chlorine levels render TA measurements in-accurate (like pH readings)? Or have I screwed up my measurements? Also, I read Sodium Hypochlorite of 7.5% on the active ingredients label, but Clorox added a note: "Yields 7.1% available chlorine". Is it correct to use the Sodium Hypochlorite or available chlorine percentages? If so, would that explain why my FC was high? (I used 7.1% instead of 7.5% in Pool Math)

Anyway, after adding the chlorine, and while waiting for it to mix in for 15 mins or so, I grabbed the brush and started scrubbing the ever-loving-daylights out of the side of the pool (I had noticed a slight green hue in the deeper end of the pool on the lower part of the walls earlier in the day). In fact, I ended up brushing the whole pool. Suction cleaner was also going to work this whole time, so I logged some vacuum and brushing maintenance in the pool math app as well.

Fast forward to about 20 mins before sunrise this morning, and I took just a Chlorine reading:

FC - 26
CC - 1.5

I expected FC to drop commensurate to the CC increase as I likely brushed some algae into the water that the Chlorine was interacting with. Instead, my FC seems to have held steady while the CC increased. Where did the extra chlorine come from?

Thanks again for all your help!

 

[Texas Splash]

So a few things to address in this post of yours:
- Use the active ingredient; not the smaller "yields" number. Chlorine or bleach is usually like 8.25%, 10%, 12.5%, etc.
- Always pour liquid chlorine and muriatic acid slowly near the return jets. It doesn't have to be on high speed unless you just want it to, but pour slowly and as you learned, watch the wind direction.
- FC drop and CC do not change at a commensurate rate. In fact, you can have algae with a CC of zero, so don't let that throw you off. Just do your best to maintain the proper FC SLAM level of "24" based on a CYA of 60.
- Acid lowers pH and eventually TA. The rate of TA drop depends on how much acid is used and how often. But don't get wrapped around the axel on TA, it's not your priority right now. A TA of 160 isn't hurting anything at this time.
- An elevated chlorine level over 10 generally impacts the pH reading which is why we say adjust the pH first, then leave it alone and focus on the FC. In some cases, a really high FC can mess with the TA test, in which case we might suggest adding a 3rd drop of R-0007. But again, there's no need to mess with the TA or even test it right now during the SLAM.

Hope that helps.

 

[Texas Splash]

Also, we have been advising members to not use Clorox liquid bleach due to the effects of fabric polymers added to their formula a few years back. Some people complained of side effects to their water. Plus. they seemed to be a bit more expensive. Your call though. Availability of chlorine and/or bleach has been tough in many areas.

 

[Mdragger88]

You mentioned the C word ( clorox )
That often has cloromax in it which are polymers that can cause foaming etc. - u don’t really want anymore of that in your pool
Try to find a source of liquid chlorine/sodium hypochlorite in the pool section of Walmart, lowes, Home Depot, menards, ace hardware etc. Often pool stores sell it in refillable jugs too. You may need to call around.
it is generally at least 10% & is free of adulterations like cloromax, scents, splashless agents, & fabric conditioners, all of which u don’t want in your bleach.

 

[wireform]

I suspect your TA isn't as high as your outcome due to the fact new reagent R-0009 has a static charge thus not giving you the true droplet size so it'll yield more smaller drops causing a higher count. See TA notes

 

[Grubby]

we have been advising members to not use Clorox liquid bleach due to the effects of fabric polymers added to their formula a few years back.

You mentioned the C word ( clorox )
That often has cloromax in it which are polymers that can cause foaming etc. - u don’t really want anymore of that in your pool

Thank you both for the feedback re: Clorox! I did try to pay attention to anything on the label about scents, or other additives. I stayed away from concentrated formulas, and while I didn't see anything about cloromax on the labels, I'll heed your advice and look for a different source of liquid chlorine/sodium hypochlorite. Leslie's is the primary pool supply store here in town and all but one of their stores was out of stock. I'll check the pool sections of those other stores you mentioned. Thanks again!

 

[Grubby]

I suspect your TA isn't as high as your outcome due to the fact new reagent R-0009 has a static charge thus not giving you the true droplet size so it'll yield more smaller drops causing a higher count. See TA notes

Ah! The instructions with the test kit instructed wiping the R-0009 cap with a damp cloth, now I know why (and I did...). I suspect that my test results may be inconsistent due to inexperience, knowing when to stop counting. TA may have been higher in the beginning - I just didn't stop at the same point (interesting note about stopping after the color stops changing, not stopping when it first changes). Thanks for the TA notes tip!

 

[wireform]

So between the drops of flip the bottle wipe the tip and go it again. Be mindful the bottle should be completely vertical or it can yield larger droplets causing the reverse count problem.

 

[Grubby]

So between the drops of flip the bottle wipe the tip and go it again. Be mindful the bottle should be completely vertical or it can yield larger droplets causing the reverse count problem.

Interesting - I'll make sure to get that bottle vertical. Are other tests in the kit this sensitive to bottle orientation and/or static build up? Or is it just the TA test?

 

[proavia]

For all the drop tests, the reagent bottles need to be held vertically. Don't force the drop off the tip, let it fully form. Dispense at about one drop per second.

 

[an1vrsy]

A couple of things I’ve noticed about our water here in the Las Vegas valley. Yes, your TA results is probably 140. Mine is. Over the summer adding MA like I do it will come down to about 100 at the end of the season. But when we add makeup water, the source water is 140. So TA will always be high but it really doesn’t matter. Manage your pH and don’t let it get above 8.0

For a chlorine source before you get your SWG going. Ace hardware sells 10%, Lowes does too and it is cheaper than HD. I haven’t been into Walmart lately but when in stock they are probably the least expensive of all for 10% chlorine.

 

[Grubby]

A couple of things I’ve noticed about our water here in the Las Vegas valley. Yes, your TA results is probably 140. Mine is. Over the summer adding MA like I do it will come down to about 100 at the end of the season. But when we add makeup water, the source water is 140. So TA will always be high but it really doesn’t matter. Manage your pH and don’t let it get above 8.0

For a chlorine source before you get your SWG going. Ace hardware sells 10%, Lowes does too and it is cheaper than HD. I haven’t been into Walmart lately but when in stock they are probably the least expensive of all for 10% chlorine.

Thanks for the tip re: Lowe's chlorine source. I found it today and it was a *much* better source of chlorine. Higher concentration and cheaper than Clorox. Plus, no Cloromax additive. Win win!

Also, glad to hear from someone else who lives here that the water has a higher alkalinity. I'm topping off about 3" of depth every other day or so right now due to heat and use, so having a higher TA makes total sense. I'll just do what you said and stay on top of the pH.

 

[mknauss]

Be careful with Lowes and HD chlorine -- they store it outside. The elevated temperatures degrade it pretty quickly. Be sure the product you buy is fresh.

Chlorine Date Code Decoder - Further Reading

www.troublefreepool.com

 

[an1vrsy]

If you live near Eastern & Windmill, Fresh Pool Supply had the best price for 12.5% and it is stored inside. For me, that’s a 30 minute drive one way so I don’t go over that way very often. Especially with my SWG.

 

[Grubby]

If you live near Eastern & Windmill, Fresh Pool Supply had the best price for 12.5% and it is stored inside. For me, that’s a 30 minute drive one way so I don’t go over that way very often. Especially with my SWG.

I'm up north - near(is) to 215 and 95 interchange. I'll double check that the stuff I bought is fresh. If it isn't, I'll take it back.

 

[Grubby]

Well folks, SLAM complete as of this morning! OCLT was 0, CC was 0, and that water is *crystal* clear. Now it's time to figure out this SWG and get it dialed in...

 

[Mdragger88]

Congrats
It looks like your banner signature says tcell 5 (which would be a little small for your pool volume & location)
But your full bottom signature says t15.
Which cell do u have?

 

[Grubby]

Congrats
It looks like your banner signature says tcell 5 (which would be a little small for your pool volume & location)
But your full bottom signature says t15.
Which cell do u have?

T-Cell-15. Thanks for pointing that out, I'll get it fixed.

 

[Grubby]

Congrats
It looks like your banner signature says tcell 5 (which would be a little small for your pool volume & location)
But your full bottom signature says t15.
Which cell do u have?

The chlorinator clearly says T-Cell-15 on it, but my banner signature choices don't include that option. Is a T-15 the same as a T-Cell-15?

 

[Mdragger88]

T-Cell-15. Thanks for pointing that out, I'll get it fixed.

That cell produces 1.47 lbs of chlorine per 24hrs
Use PoolMath effects of adding - select swg, then search for your cell.
U can play around with run times & percentages.
Most with a vs pump run it all the time on a lower rpm (1500/1600) & then just adjust the swg percentage to produce the amount of fc needed to maintain target level daily)