FC is 1.5 TC is 5.0 how much lithium hypo or cal-hypo to shock & fix?

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Lynnster52

Well-known member
Apr 29, 2018
54
Cos Cob CT
Hi - I'm having hard time trying to avoid following Leslie's Pool's advice so want to shock newly opened pool that is clear and sparkling but has cc issue.
Pool is 26000 gal. In-ground, vinyl liner with cartridge filter.

FC is about 1.5
TC is 5.0 (according to Leslie's)
PH is 7.6
CYA is low at 10
CH is 100 (which should be ok for vinyl)

Even though pool looks great and has no odor, it seems I still need to shock. I have 2 types of shock on hand; lithium hypo and cal-hypo. I've already screwed up by not putting enough lithium hypo in all at once (did it over 2 days). So now I need get it right. Can I assume that using the Cal-Hypo might be the way to go considering the low calcium, and then use lithium to shock the remainder of the season? (CYA is low but that will come up once we get the tri-chlor pucks in the auto feeder; I just want to fix the CC issue first)
Tks!
 
Using pucks to raise CYA is a slow process. I'd advise to get some stabilizer in there and raise CYA to 30-40. Otherwise, you risk the sun burning off your FC very quickly. Also, I wouldn't trust Leslie's tests. You should get your own test kit and test the water yourself. Get either a TF-100 or Taylor K2006C as they are the only ones with the high quality chlorine test.
 
That TC reading is fishy.

You have a clear pool and available chlorine, albeit not very much.

I would not SLAM that pool.

Rather, dose enough CYA to get to 30 ppm for now and then keep your FC around 3-4 ppm while you sort things out.

You are doing yourself no favors allowing others to test your water.
 
Need to shock. CYA is 10. Ok to use di-chlor?

Hi & help pls!
Opened pool early & water is only 50º. Pool water opened crystal clear/sparkling, but I used too little lithium to shock it (tks to Leslie's for lousy advice of using just 4-5 lbs of lithium & then telling me to add 2 more lbs the next day when reading only went from 0 to 0.6 ppm! I knew this was wrong advice so here I am!)

First, at least pool now has a chlorine reading, but it's only 0.6 ppm. I want to get it up to 5 or 10 ppm for a good "opening" shock (there were loads of worms at the bottom & some leaves) As I said, pool was clear when cover came off, so it's a matter of either more lithium or di-chlor to shock properly.

Our CYA is 10 - I read that under 30-50 prevents chlorine from working, so I'm thinking shocking with di-chlor now will raise CYA a bit and just this once. (lithium will not help CYA & is so expen$ive so will use lithium later in season for shock once CYA is normal & water warmer)

PH & alkalinity are are perfect.

Tri-chlor pucks are in auto feeder & turned to "full" but chlorine level is not rising in 2 days now, but holding at 0.6 ppm (I think water is either too cold, or pucks from last year have degraded, or the cya is so low the chlorine can't do its job, therefore hoping someone will agree to go with di-chlor to shock)

Question: Leslie's guy said NOT to dissolve di-chlor shock in large bucket of water ("it could explode") Really? I intended to dissolve 1 bag at a time in a 5 gal bucket of warm water & then add to pool. If I don't do that, I know from past years that shocks, other than lithium, will not dissolve in 50º & will end up on bottom of liner.

Pool is IG vinyl liner, 26,000 gal. I figure 2 bags should be good for now as pool is clear & sparkling. The reason to shock: chlorine level is low & there is a CC issue according to my test kits, strips & Leslie's testing.

Finally, is it true that after shocking, chlorine level should not drop more than 1 ppm after 8-10 hours to be considered successful? (and if it does drops more than 1 ppm, one needs to reshock (likely using less) wait 8-10 hrs & retest, hoping the 2nd time holds?) Never knew this in 28 years of owning this pool & never had an issue so I guess it was dumb luck that our pool is always sparkling!

Tks for any input about the di-chlor!
 
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Re: Need to shock. CYA is 10. Ok to use di-chlor?

i'm sure some of the regulars will chime in here any minute, but i'd strongly suggest going to the "pool school" tab and reading up on water chemistry. the fundamentals of the TFP method are only to add chemicals that you know the ingredients, and only when you need that specific chemical. most people here maintain their pool with liquid chlorine (common household bleach), baking soda, and muriatic acid--all of which are available at your local grocery store, walmart or home depot (okay, you may need to look around for muriatic acid but should be available at hardware stores, home depot, lowes, etc.)

the dichlor and trichlor pucks and/or shock are adding CYA to your pool, whether you like it or not. eventually your CYA level will reach the point that you can't maintain adequate free chlorine (FC) and will need to drain some of your water. pretty sure lithium is a gimmick and not really adding anything positive to your water chemistry (no pun intended), other than costing you more money at the pool store.

you will need your own testing kit so you get consistent results. the two recommended here are the TF-100 from tftestkits.net or the Taylor k2006. http://www.troublefreepool.com/content/124-pool-test-kits-comparison

once you take control of your own water, and only spend money on chemicals that you really need--you'll never go back. lots of great, knowledgable and helpful people here. sit back, read a little bit, and ask questions. but please, do your own water testing...

for now, 2 gallons of regular unscented chlorine bleach (6%) will get you to a FC of 5, which should keep nasties at bay while you're sorting some of this out. you said your water is crystal clear, so i would think that should buy you a lil time.
 
sorry, i didn't answer your initial question.

yes, dichlor would be fine to use to raise your FC, but recognize that you will be adding small amounts of cyanuric acid (CYA) with each dose. it's probably ok for now if your CYA level is really 10.

i'm pretty sure dissolving dichlor in a bucket of water will not cause it to explode (after all, isn't your pool one giant bucket???)
incidentally, 1# of dichlor will raise your FC by 2.6 and raise your CYA by 2.3.
 
Re: Need to shock. CYA is 10. Ok to use di-chlor?

thank you! I will get some bleach in there right now! I've been reading up here and elsewhere. Apparently I've been here before but forgot! Getting old sucks!

- - - Updated - - -

I brought water sample inside & waited til it got to room temp & retested just for CYA and got 38 rather than the 10 that Leslie's said it was (when 50º). Can 50º water mess with CYA test? tks!

- - - Updated - - -

tks! Agree & will get another kit. I have a HTC kit that tests for most everything but I guess I should be using a Taylor & wld be nice to see if both tests agree. I also have basic OTO 2-way test kit.
 
Re: Need to shock. CYA is 10. Ok to use di-chlor?

sandman98 said:
d strongly suggest going to the "pool school" & reading up on water chemistry..."

Will take refresher course as this year, it's the methods of shocking that confused me, along with the 50º water.

"most people here maintain their pool with liquid chlorine (common household bleach), baking soda, and muriatic acid.."
Yes & I'm thinking of switching to liquid chlorine this year! I do worry about having to dose pool daily however. That's not always possible so the reason for puck in auto feeder.

trichlor pucks and/or shock are adding CYA to your pool... eventually your CYA level will reach the point that you can't maintain adequate free chlorine (FC) and will need to drain some of your water."
Yes, I know that & we had to drain half the water last year for the first time. Took a long time but it did happen. That's when we bought the bucket of lithium, but seems we went back to tri-chlor as we go on wkend excursions & can't maintain daily all the time. But I do know about the CYA. My concern is whether the 50º water is skewing the testing.

"pretty sure lithium is a gimmick.."
I hope not! It's works and adds nothing else to the pool (I guess much like liquid chlorine, so that alone makes sense UNLESS we aren't home to dose pool daily) DOES one have to dose liquid chlorine daily?

you will need your own testing kit so you get consistent results
For 28 years, we used basic 2-way oto and I bought HTC 6-way 2 years ago. This was 1st year I had Leslie's test the water, but will order a Taylor now! Tks!

but please, do your own water testing.
will do from now on! (came from Leslie's the other day with huge bucket of CA and Phos Free, but read up on them and both bogus for my vinyl pool. Returned/refunded. The clerk said I'll take the CA back but you really really need the Phos Free....I say "stop it" to him & he finally got the picture. I was pretty p.o'd as felt so taken advantage of (sorta sweet, 66 yr old female....but tough when screwed over..)

for now, 2 gallons of regular unscented chlorine bleach (6%) will get you to a FC of 5, which should keep nasties at bay while you're sorting some of this out. you said your water is crystal clear, so i would think that should buy you a lil time.
YES and big hug to you & others here for setting me straight. Going to find me some (unscented) clorox!But will wait for pool to shade over as hot/full sun right now!
Click to expand...
 

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YAY for Pool School and PoolMath! It worked for this newbie to it!!

I came here this week & back now to say tks! Highly recommend Pool School & Pool Math calculator (see tabs above) as they saved me today when I woke up to a 0 chlorine reading & on the verge of big trouble...

We opened pool early to sparkling/clear water but there was CC after bad advice re shocking (powered lithium - way too little over 2 days yet!) as per Leslie's rep..(do not use them ever! Great way to increase sales of buckets of lithium powder!!)

Water was stuck at FC of 0.6 & TC of 5 = CC issue & need to shock (Leslie's tested water & I assumed I was advised on shocking with the lithium but rep just raised it from 0 to 0.6 via his advice!)

So I came here & was advised to got to Pool School & use PoolMath (see tabs above). GREAT ADVICE!

Also advised to get FAS/DPD test for chlorine. On it's way but making do with strips & 6-way HTC otc kit until it arrives.

Because water was FC: 0.6, I shocked with di-chlor (deliberately as our CYA was under 30) & felt that between the di-chlor & the auto feeder, we could get by until the FAS/DPD test arrived.

All good for 3 days until FC was 0 this am. (not good for pool that is still waiting for a proper shock)
I plugged numbers into PoolMath calculator which said I needed 4 gals of 8.2% bleach I easily got at grocery store. Did right away & 20 mins later water tested at FC:10 TC:10 CC: 0 (using strips & HTH 6-way test kit). CYA:30, TA:90, CH:150, PH:7.8 Temp: 63º. Turned on auto-feeder with tri-chlor as we need something until the FAS/DPD test kit gets here & we switch to liquid chlorine for both shocking & as daily sanitizer AFTER 28 years of using everything from lithium, di-chlor, tri-chlor, cal-hypo...it's crazy to think how much easier maintaining our pool could have been! It will be now though!

Last year we had blooming issues from Aug on, but now I know why so we'll avoid that IF we stick to advice given here!

Just wanted to say thanks to those who run this site! Wee'll switch to liquid chlorine as daily sanitizer & shocking, & then only use auto feeder when we go on vacation!
 
SLAM Length

BattleOfYakima said:
I once had a SLAM that lasted 1.5 hours and only three bleach additions....
Click to expand...

I'm also new to TFP & doing best I can with strips & HTC 6-way kit until my Taylor arrives (Rebecca said today, but tracking says Mon) so flying by seat pants until then.

Could u pls explain how a SLAM can be over in 1.5 hours? I spent 5 hrs in Pool School & took notes but guess I missed something. I thought I needed to keep testing for at least 10 hours?

I began with sparkling clear water, but had CC issue. Used PoolMatch & no CC 15 mins later but I tested 3 hrs later & 10 hours later to ensure no CC. At what point is the shock over? Now it's 24 hours later & CC is still 0 (using strips & HTC 6-way until my Taylor arrives - so a bit of guessing) but FC & TC went from over 10 down to 5 for both. Does this mean I need to add more chorine? How long does one keep shock level that PoolMatch recommended?

Until Taylor gets here, should I add more bleach to bring strip readings back up to 10, or just hold FC and TC at 5 & only shock again if I get CC over 0.5. (will brush & vacuum today as there is now some debris in deep end pit - & retest after in case of hidden algae brings on CC?)

Thank you! Please tell me I'm sort of "there" with my understanding. If not, send me back to PS but pls tell me what chapters to reread! ;)
 
Re: SLAM Length

Lynnster, just hang tight for now. Without the test kit, there's not much you can do accurately, so just add some bleach (about 1 gallon) each day to keep thing from getting any worse. Once the kit arrives, you'll be able to follow the SLAM page accurately. No need to compare your situation, duration, or processes used to anyone else's. You sound to have a good understanding. Now you just need the test kit. :)
 
Re: SLAM Length

Lynn, I think Yak was being "silly" when he said that. It was more like all he needed to do to get the cc he saw was add enough chlorine to get it to SLAM level and that took care of what ever was going on so it only took 1.5 hours.

You have a good understanding and doing pretty good with one hand tied behind your back with the baby test kit and strips. Once you get you grown up test kit you will be good to go.

Kim:kim:
 
sandman98 said:
yes, dichlor would be fine to use to raise your FC, but recognize that you will be adding small amounts of cyanuric acid (CYA) with each dose. it's probably ok for now if your CYA level is really 10 - Yes it truly was 10...it's about 25 now. We shocked with di-chlor (before getting Taylor DPD/FAS test) but CYA hasn't risen much. I have no way to check below 30 (Leslie's told me it was 10 early in the week). When I test it, I can see the spot at 30, but not when I add drops up to the brim, so I'm assuming it's now just under 30 & leaving it. We're running the auto chlorinator with tri-chlor pucks. Seems raising CYA can take days to show up on a test, so not adding any extra as don't wan't to suddenly have high level. We want to be able to use pucks when we go away while pool is open.

i'm pretty sure dissolving dichlor in a bucket of water will not cause it to explode (after all, isn't your pool one giant bucket???)Exactly! We dissolved it in a 3 gal bucket, 1/2 bag at a time, and we are still in one piece!
incidentally, 1# of dichlor will raise your FC by 2.6 and raise your CYA by 2.3.
Click to expand...
So I guess we raised the CYA by 4.6 then, and with the pucks in the auto-feeder, it should come up to 30 soon, right? (water temp went from 50º to 66/67º so I'm thinking pucks are putting CYA very slowing. I did bring sample inside & brought to room temp but test still showing dot (barely) at the 30 level, but obscures soon after. Gotta assume it rose up into the high 20's by now & still rising due to pucks. If I'm wrong, pls set me str8! Tks!
 
Re: SLAM Length

Texas Splash said:
Lynnster, just hang tight for now. Without the test kit, there's not much you can do accurately, so just add some bleach (about 1 gallon) each day to keep thing from getting any worse. Once the kit arrives, you'll be able to follow the SLAM page accurately. No need to compare your situation, duration, or processes used to anyone else's. You sound to have a good understanding. Now you just need the test kit. :)
Click to expand...
Thank you! Kit arrived but had wrong reagent for CC....Found bottle at Leslie's
SO WE ARE NOW IN THE MIDST OF OUR FIRST SLAM!! YIPPEE - what a great way to test chlorine levels!
QUESTION: How long after adding the CC testing reagent (R0003)does one wait to read it as clear? It comes up clear (no pink) upon 5 drops (but I left vial & 10 mins later there was a slight blush to it. The instructions don't say how long to wait, if at all. I just assumed if clear after 5 drops & a swish, all was good. Tks!.
 
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