1st thread question about Calcium Hypochorite and Trichlor Chlorine Tablets

MAGnet_ManNY

Member
Apr 22, 2021
16
Miami Lakes/Florida
Hi, I've read (more like devoured ;)) the articles on TFP related to Chlorine, Calcium, SLAM, metals, etc. I just got my 15,620 gallon plaster pool resurfaced here in Miami, FL. I've read the warnings in some articles here regarding using Tri-Chlor Chlorine Tablets and also the warnings on Calcium Hypochlorite and YES, I read the warning to NEVER mix because of dangerous possible reactions/explosion. The owner of the company that resurfaced my plaster pool warned me against using any Calcium products for at least 6 months. Unfortunately, before I got my pool redone, I had purchased a 50 lb BUCKET of Zappit Swimming Pool Chlorine 73% Hypochlorite :eek: that cost me well over $100. I had intended to use it instead of Chlorox Xtra Blue Shock which I've used before my pool was resurfaced. Right now, I am doing SLAM/shock with Liquid Chlorine.

So, QUESTION 1: After 6 months, can I or should I use the 73% Hypochlorite just for SLAM purposes when I need to shock the pool and then when I use up the 50 lbs move to liquid chlorine for SLAM purposes (which I believe is the TFP preferred SLAM method)?? Or given long term effects, should I just try to resell it somewhere (It's UNOPENED/UNUSED) and if so where could I resell it, eBay?? Please enlighten me here.

In the meantime, I am currently using liquid chlorine (10% strength from Walmart) for keeping chlorine levels stable but the same gentleman that I mentioned above who advised against calcium products for six months, advised that I used chlorine tablets in a floating device to keep chlorine levels stable. I have 40-50 unused Chlorox XTra Blue Chlorine/Trichlor tablets that I previously used before in my in-line Chlorinator and before I read some of the Trichlor warnings and warnings against Chlorox products here.

QUESTION 2: Should I consider using up this supply of 40-50 Chlorox Xtra Blue Chlorine/Trichlor tablets and then either switch to another chlorine tablet brand/type or go liquid chlorine from here out? Or given its potential long term effects with CYA and/or metals, should I just bite the bullet and use another chlorine type tablet or liquid chlorine for chlorine maintenance? Please advise.

Obviously, from a cost perspective, the ideal would be to use up my initial investement of Chlorox Xtra Blue Chlorine/Trichlor tablets this summer and then in mid-fall start using up the 73% Calcium Hypochlorite for SLAM/shock until I finish the 50 gallon bucket. I can then transition to liquid chlorine. BUT I don't want to do follow this path at the expense of future problems especially with pool being freshly resurfaced. Looking forward to your comments. :cool:
 

IceShadow

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Jun 8, 2019
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Milwaukee, WI
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Clorox Xtra Blue products have copper. Copper never leaves the pool unless the water does and can cause staining and green hair if it accumulates. You don’t want to use those.

The cal-hypo will add some calcium but there’s more leeway there. So you might be able to use that. What are your pool’s current chem levels?
 
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HermanTX

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May 20, 2020
1,716
Katy TX
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It would be best to post your results of your pool water test. It is also best to do your own testing by purchasing a suitable test kit - see Test Kits Compared. Also see Recommended Levels for your pool.
Using Cal Hypo increases calcium in your pool and if your CH test is already in the desirable range then it is best not to use it.
Thus the need to see what your test results are now.

Using tablets are ok for short periods of time (like away for 5-7 days) but not any with copper what appears is what you have. For longer term you need to switch over to Liquid Chlorine (LC). You also need to test for CYA such that you can establish your FC level properly based on FC/CYA Chart
 
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DeanP66

Well-known member
Mar 26, 2014
1,192
San Jose, CA
Depends on what your fill water is like. I'd advise you to test your fill water for pH, TA, and CH just so you know what you're working with. I have a fill water with extremely high TA (330) and high CH (350), so I know that over time as I top up the water from evaporation, I will be increasing both. Because of that, I don't put anything in the pool that contains calcium in it.

Back to you, if your CH is low to begin with, you could save the cal hypo and use it down the line. Just be aware that it will increase your CH a little bit everytime you use it.

Definitely, do NOT use those clorox Xtra Blue tablets. They contain copper and will eventually stain your pool.

Stick with liquid chlorine for now and supplement with the cal hypo if you want. The couple of hundred dollars that you spent on those materials aren't worth the headache of premature staining and introducing other problems.
 
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MAGnet_ManNY

Member
Apr 22, 2021
16
Miami Lakes/Florida
Clorox Xtra Blue products have copper. Copper never leaves the pool unless the water does and can cause staining and green hair if it accumulates. You don’t want to use those.

The cal-hypo will add some calcium but there’s more leeway there. So you might be able to use that. What are your pool’s current chem levels?
Thanks for the quick reply. I had that feeling about Chlorox having read about the Copper Issues but oh, well. I can bite the bullet on this if that's for the best.

I just finished SLAM recommendations after a long weekend of swimming because of my wife's birthday. I last adjusted levels 5 days ago so this afternoon my PH level was very high at 8.2 with Chlorine (FC, TC) at 0. So per app recommendations I added 240 fl oz of (10%) Liquid Chlorine and 23 fl oz of 34.5% Muratic Acid. CYA is at 30 and recommendation is to add 59 fl oz of stableizer but I decided not to do that right now since I was doing SLAM along with Muratic Acid to take care of Chlorine and PH issues. Also, my Total Alkalinity is at 110 right now, I saw that one of the recommendations on the app was to bring PH down to 7.2 to bring TA to desired levels of 70-90 but again just put in recommended 23 fl oz to bring it down to 7.6. I decided to hold off for at least 24 hours regarding TA and CYA level because I just SLAMed it. Is that OK to wait, or should I just add stableizer and more Muratic Acid per CYA/TA recommendations now?
 

IceShadow

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Jun 8, 2019
2,532
Milwaukee, WI
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Ok so - SLAM is usually just used to address a specific problem, usually algae. Is your pool clear? CC is 1ppm or less, and no chlorine loss overnight? If so, no need for SLAM.

What is your current FC? If it’s over 10 the pH test will show artificially high.

You will probably want to put more CYA in for a Florida climate to get it to 40 or 50, but no rush. If you notice you’re losing a lot of FC during the day (but not at night), you can bump it up some. If you really do need to SLAM, then keep at 30 until it’s done to keep FC needs lower.

Don’t worry about TA. Your pH will drift up over time and you’ll add acid, which will lower both pH and TA. So it will lower over time on its own.
 

HermanTX

Gold Supporter
May 20, 2020
1,716
Katy TX
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I just finished SLAM recommendations after a long weekend of swimming because of my wife's birthday. I last adjusted levels 5 days ago so this afternoon my PH level was very high at 8.2 with Chlorine (FC, TC) at 0. So per app recommendations I added 240 fl oz of (10%) Liquid Chlorine and 23 fl oz of 34.5% Muratic Acid. CYA is at 30 and recommendation is to add 59 fl oz of stableizer but I decided not to do that right now since I was doing SLAM along with Muratic Acid to take care of Chlorine and PH issues.
At a CYA of 30, your target FC is 4-6ppm but your SLAM level is 12ppm. You would SLAM only if you had algae. If you are just trying to raise FC quickly because of the high bather load then target 6ppm using LC.
 

IceShadow

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TFP Guide
Jun 8, 2019
2,532
Milwaukee, WI
Pool Size
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Vinyl
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Liquid Chlorine
Just saw your 0 TC and FC. You don’t want that! Add liquid chlorine daily after testing to bring back to minimum levels. You should never have your FC drop below the recommended levels or algae can take hold.
 

MAGnet_ManNY

Member
Apr 22, 2021
16
Miami Lakes/Florida
At a CYA of 30, your target FC is 4-6ppm but your SLAM level is 12ppm. You would SLAM only if you had algae. If you are just trying to raise FC quickly because of the high bather load then target 6ppm using LC.
Thanks for the info. I decided to SLAM because pool water was not clear and color though not green was not where it needs to be and about 24 hours away from trending green (this from my previous unfortunate experience with my pool previously so I guess I may have jumped the gun here).

I guess, I may also be a bit confused with regard to SLAM. I had equated it to shocking the pool. Now, I have seen recommendations that you shock the pool after a rainstorm but not sure how that fits for South Florida summers where it showers, usually briefly, every afternoon. How often do you need to SLAM the pool? What about dealing with daily summer rains, which while brief in time, can be a strong shower in intensity? I guess I need clarification on SLAM.
 

MAGnet_ManNY

Member
Apr 22, 2021
16
Miami Lakes/Florida
Just saw your 0 TC and FC. You don’t want that! Add liquid chlorine daily after testing to bring back to minimum levels. You should never have your FC drop below the recommended levels or algae can take hold.
Thanks, I probably should have tested and applied chemicals last night but since it was my wife's birthday and my eldest son just got 2nd Covid vaccine, it slipped through the cracks until today but given the change in clarity and color that I noticed today, I saw we were on our way to algae taking hold so I decided to opt for the SLAM thinking it was analagous to shocking the pool.
 

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HermanTX

Gold Supporter
May 20, 2020
1,716
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
I guess, I may also be a bit confused with regard to SLAM. I had equated it to shocking the pool. Now, I have seen recommendations that you shock the pool after a rainstorm but not sure how that fits for South Florida summers where it showers, usually briefly, every afternoon. How often do you need to SLAM the pool? What about dealing with daily summer rains, which while brief in time, can be a strong shower in intensity? I guess I need clarification on SLAM.
Pool stores use the word shock which is raising the FC for a short period. Under TFP methodology, if you maintain your FC in the target range for your CYA regardless of rain or sunshine you should be good. So maybe after a rain you may need to add a little more LC but it is not shocking as the pool store would indicate.

SLAM is if you have an issue - best explained by this
 

MAGnet_ManNY

Member
Apr 22, 2021
16
Miami Lakes/Florida
Awesome! Thanks for the videos. I have seen several TFP videos but somehow missed these:rolleyes:. This is a great help to understanding this and makes sense because I kept rolling in my mind the need to SLAM after every thunderstorm and that didn't make sense so I'm glad you guys have set me straight.
 

DeanP66

Well-known member
Mar 26, 2014
1,192
San Jose, CA
Once you get the hang of things, you won't have to shock your pool at all if done right. The key is keeping your FC in the right range, not topping it off one day and waiting for several days for it to hit zero. For a CYA of 30, you want to keep your FC in the 4 to 6 range, and never let it get below 2. Your pool will use between 2 to 4 ppm daily when clean during the summer, so you have to replace it daily to keep up.

For the SLAM, the key is Maintaining the shock level, which for you at CYA 30 is 12ppm. So, the key to a quicker SLAM as opposed to a longer one is checking the FC several times a day and topping it back up to that same 12ppm. That will kill everything in the pool the fastest and clear up your water.

One other thing, unless I'm missing something, to lower your pH from 8.2 to 7.6 with a TA of 110 in 15600 gallons of water, I come up with 92 oz of 31.45% muriatic acid. 23 oz won't drop it very much.
 

joemkraus

Well-known member
Sep 23, 2019
97
Saratoga, CA
since started following TFP and only use LC and maintain min levels, I have not shocked my pool since initial SLAM 2 years ago, pool water has been crystal clear all of the two years!
 
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