70% Powder Chlorine - 1KG per day for 20,000 gallon pool in tropics - zero reading

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,895
Laughlin, NV
If you put chlorine into water without CYA and the sun shines on it, the half life of that chlorine is under an hour. So you need some CYA in the water.

What does the water look like? I doubt you need to drain.
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
If you put chlorine into water without CYA and the sun shines on it, the half life of that chlorine is under an hour. So you need some CYA in the water.

What does the water look like? I doubt you need to drain.
first ty for taking the time to help desperate swim guy! this is the pool today - water looks great right? but if tester says in no chlorine a day after adding 2KG then is something wrong right? My strip tester says is zero CYA so first step is to get some stablizer in there? then change to the chlorine tablet that has built in stabilizer? we have a lot of evaporation so we add 4 inches of water every 2 days so is always lots of new water. that a plan or ?

99992
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,895
Laughlin, NV
Yes to adding the stabilizer. But no to the tablet on a daily basis. They will add too much stabilizer. Evaporation does not remove stabilizer from the pool water. Use liquid chlorine on a daily basis. You can use tablets when your stabilizer goes down, but right now, you have no way to test that.
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
Merged threads - mknauss - TFP Mod

We are in the tropics- same as Miami weather. Pool chemical guy sold us 70% Chlorine powder. We add - check next day - gone - add again. On it goes. Now we find out is no CYA in our pool so of course sun burns it off. Then find out is tablets - has 90% chlorine with build in stabilzier so UV not burn it off so fast. So I can't figure out why anyone would use anything else? Next thing I don't know - we have 0 cya. So should we add stabilizer and then start to use the tablets or if we just use the tablets will that add cya as it goes along and that is good enough. Appreciate your feedback - am new to this.
 
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kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
38,286
Tallahassee, FL
They are fine to use until you get too much CYA in the pool. Here is a chart that shows you the ratio: Chlorine / CYA Chart - Trouble Free Pool As you can see the more CYA you have the more FC you need. The only way to get rid of excess CYA is to drain and replace some of the water.

There are some tablets that have CH (Calcium Hardness) in them. Again you do need some CH but too much is not a good thing. Guess how you remove CH...............yeap the save drain and replace as above.

Now if you have a lot of rain in your area then you can balance that with the tablets/powers as the rain will help you replace "clean" water in your pool.

The most important thing is to have a good test kit so you can keep an eye on all of the levels. Here is a link that shows you the different test kits we use: Test Kits Compared - Trouble Free Pool I will tell you I think the TF-100 is the best bang for the buck as it has more of the regents we use the most.

Kim:kim:
 
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Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,977
San Dimas, CA (LA County)
Lots and lots of people have tried that.... and they ended up here with a green pool. The problem is that the chlorine in those pucks goes away, but the CYA remains and builds up, requiring higher and higher levels of chlorine to remain sanitary and algae-free. Here's something I wrote a few years ago.


We'll take a 16000 gallon pool, because that's what I have. On a fresh fill, prominent national pool chain recommends 2.5 pounds pf stabilizer per 10,000 gallons, which works out nicely to 4 pounds which brings CYA to 30.

With an average loss of 2 PPM/Day or 14 ppm/week, I'll have added 8.6 PPM/CYA if I used trichlor pucks perfectly. And they recommend a weekly "shock" of dichlor between 5 and 10 FC.. 2-3 oz per 10,000 gallons. Split the difference; I'll add 4 oz. CYA went up another .9.

So..by the end of week one, I have added 9.5 more CYA. It is now 39.5. Minimum FC for that is 3, so I'm probably okay.

Week two, up to 49 CYA.
Week three, 58.5. Minimum FC should be 5, but they recommend 3 as ideal, so the pool looks a bit hazy. So I'll toss in a little extra dichlor "shock" to jack FC up to 10. Which adds another 6.4 CYA. Keeping count? We're up to 64.9 now.

That caught the algae just in time.. we had two weeks of good luck. A steady diet of pucks and 4 oz. "shock" each week only added another 19, up to 73.9 now.

Week 6 it started looking funky, so we "shocked"it once again. CYA is up to 99.3. But minimum FC to keep algae at bay is 8, and we're still holding things to 3, because prominent national chain's preprinted sheet shows that as ideal. So algae got a toehold and the pool has a bit of a tint. So we throw two whole bags of dichlor in which jacks it another 7.6. By the time week 7 is over, we're at 116.4, because we had pucks in the floater the whole time.

So...in 7 weeks, from 30 to 116.4. Let's say there are no more algae outbreaks because they sold me a huge bucket of phos-free and another of yellow-out monopersulfate "shock" Nothing but the pucks and the extra 4 oz of dichlor "shock" weekly. So the next 7 weeks added 66.5, which brings the total to 182.9 CYA.

Now if we didn't understand this and things looked a bit hazy, we might throw an extra puck or two in the floater every couple weeks, which will drive it over 200 easily.

It's a vicious cycle. You have inadequate free chlorine for the stabilizer level so you get algae, so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator and then all the sudden, your pool turns cloudy and green. It wasn't all the sudden. It was building for weeks.​
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
Lots and lots of people have tried that.... and they ended up here with a green pool. The problem is that the chlorine in those pucks goes away, but the CYA remains and builds up, requiring higher and higher levels of chlorine to remain sanitary and algae-free. Here's something I wrote a few years ago.

We'll take a 16000 gallon pool, because that's what I have. On a fresh fill, prominent national pool chain recommends 2.5 pounds pf stabilizer per 10,000 gallons, which works out nicely to 4 pounds which brings CYA to 30.​
With an average loss of 2 PPM/Day or 14 ppm/week, I'll have added 8.6 PPM/CYA if I used trichlor pucks perfectly. And they recommend a weekly "shock" of dichlor between 5 and 10 FC.. 2-3 oz per 10,000 gallons. Split the difference; I'll add 4 oz. CYA went up another .9.​
So..by the end of week one, I have added 9.5 more CYA. It is now 39.5. Minimum FC for that is 3, so I'm probably okay.​
Week two, up to 49 CYA.​
Week three, 58.5. Minimum FC should be 5, but they recommend 3 as ideal, so the pool looks a bit hazy. So I'll toss in a little extra dichlor "shock" to jack FC up to 10. Which adds another 6.4 CYA. Keeping count? We're up to 64.9 now.​
That caught the algae just in time.. we had two weeks of good luck. A steady diet of pucks and 4 oz. "shock" each week only added another 19, up to 73.9 now.​
Week 6 it started looking funky, so we "shocked"it once again. CYA is up to 99.3. But minimum FC to keep algae at bay is 8, and we're still holding things to 3, because prominent national chain's preprinted sheet shows that as ideal. So algae got a toehold and the pool has a bit of a tint. So we throw two whole bags of dichlor in which jacks it another 7.6. By the time week 7 is over, we're at 116.4, because we had pucks in the floater the whole time.​
So...in 7 weeks, from 30 to 116.4. Let's say there are no more algae outbreaks because they sold me a huge bucket of phos-free and another of yellow-out monopersulfate "shock" Nothing but the pucks and the extra 4 oz of dichlor "shock" weekly. So the next 7 weeks added 66.5, which brings the total to 182.9 CYA.​
Now if we didn't understand this and things looked a bit hazy, we might throw an extra puck or two in the floater every couple weeks, which will drive it over 200 easily.​
It's a vicious cycle. You have inadequate free chlorine for the stabilizer level so you get algae, so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator to raise FC which also raises CYA which means you need more FC so you turn up the chlorinator and then all the sudden, your pool turns cloudy and green. It wasn't all the sudden. It was building for weeks.​
Someone said to just buy Stabilizer and add bleach? Is that the plan then?
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
Yes to adding the stabilizer. But no to the tablet on a daily basis. They will add too much stabilizer. Evaporation does not remove stabilizer from the pool water. Use liquid chlorine on a daily basis. You can use tablets when your stabilizer goes down, but right now, you have no way to test that.
Ordered the stablizer. Going to look for bleach tomorrow - here they sell Zonrox - what you buy to do cleaning and laundry. Will it say what % it is is on it? What do we want to make does NOT have - just buy regular one I guess eh? And any idea how many oz of bleach per day for 20,000 gallon pool? Ty so much - am giving the tablet chlorine a pass.
 

mknauss

Mod Squad
TFP Expert
May 3, 2014
15,895
Laughlin, NV
The chlorine powder adds chlorine and calcium. If your calcium hardness of your water is low, you can use it. But you cannot measure it. If you use it, you may get scale. Up to you.
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
The chlorine powder adds chlorine and calcium. If your calcium hardness of your water is low, you can use it. But you cannot measure it. If you use it, you may get scale. Up to you.
So by using bleach what are you adding? Calcuim is in the powder as chlorine gas is attached to it. What do they add to bleach to make it attach and what does that add to the pool?
 

daveondave

New member
Apr 20, 2018
4
Pottstown, PA
Magandang araw,

What part of PH are you in? I have been there a few times, most recently in 2013 in Tanauan, Leyte. I was with a medical team after Yolanda came through.

To answer your first question above, yes, basically. Chlorine without CYA disappears amazingly quickly. But you can probably bring it back if you act pretty quickly. You'll need a LOT of chlorine and a decent amount of CYA (stabilizer.) You won't make any real progress on your chlorine with your CYA being up to normal. I got sloppy and let my CYA drop last summer. I got so frustrated adding chlorine with no result until I realized what had happened to my CYA. I won't do that again!

You need to get your chlorine up pretty quick, or the algae will be all over you. BUT, if you don't have your CYA in the 30-50 range, your chlorine will burn off really quickly, especially on sunny days. pH is also really important, in order to provide the proper environment that will help keep the algae and other unwanted guests in check. You can do them concurrently, as long as you wait in between. Pool school is really your best bet (link below) but here's the crash course - get your pH around 7.2-7.5, then get your CYA up into the 40-50 range (at least 30) and then get your chlorine up into Shock territory. Exactly how much chlorine depends on your CYA level, (chart: Chlorine / CYA Chart - Trouble Free Pool ) If you can get your CYA to 40, then blast your chlorine to 16 for a few days at least. If you test it every day and you see your chlorine start to stabilize (not drop fast from day to day) then you are in a good place and can drop your chlorine to normal levels.

You can work on your pH, CYA, and chlorine all in the same day, but you cannot add them at the same time! Make sure you give an hour in between with your pump running high that whole time. It is always best to add the chlorine after sundown to keep it from burning off right away, and actually having an effect on your water.

So... pH must be reasonable for a healthy environment. CYA must be 30-50 to keep your chlorine from disappearing. Get your chlorine to shock levels until you see it stabilize over a number of days, then bring it down to normal levels.

To make it much, much easier, get a good test kit (strips are nearly useless, and sometimes lead you in the wrong direction) and get the Pool Math app for your phone. But read Pool School as well for a real understanding. It will start to make sense quickly.

I hope things turn around quickly for you.

Peace,
Dave

 

daveondave

New member
Apr 20, 2018
4
Pottstown, PA
I just saw that you are adding 2" of water per day. It may really help you to save water, and also to have an easier time with your chemicals, to get a cover for the pool. Some people buy them for keeping the water warm, which I don't think you need to worry about, but it does keep you from losing water, which helps keep your chemistry more stable. Where I live is very humid and rains a lot, so evaporation is not too bad for me, but the rain really changes my chemistry. Anything to stabilize your water will help you a lot. Try a cover, if you can afford it. You can get full-size covers, small round covers that you use several of, or even chemical "covers' that help prevent evaporation. I have only used the full-size covers, so I cannot comment on the others.
 
Last edited:

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
Magandang araw,

What part of PH are you in? I have been there a few times, most recently in 2013 in Tanauan, Leyte. I was with a medical team after Yolanda came through.

To answer your first question above, yes, basically. Chlorine without CYA disappears amazingly quickly. But you can probably bring it back if you act pretty quickly. You'll need a LOT of chlorine and a decent amount of CYA (stabilizer.) You won't make any real progress on your chlorine with your CYA being up to normal. I got sloppy and let my CYA drop last summer. I got so frustrated adding chlorine with no result until I realized what had happened to my CYA. I won't do that again!

You need to get your chlorine up pretty quick, or the algae will be all over you. BUT, if you don't have your CYA in the 30-50 range, your chlorine will burn off really quickly, especially on sunny days. pH is also really important, in order to provide the proper environment that will help keep the algae and other unwanted guests in check. You can do them concurrently, as long as you wait in between. Pool school is really your best bet (link below) but here's the crash course - get your pH around 7.2-7.5, then get your CYA up into the 40-50 range (at least 30) and then get your chlorine up into Shock territory. Exactly how much chlorine depends on your CYA level, (chart: Chlorine / CYA Chart - Trouble Free Pool ) If you can get your CYA to 40, then blast your chlorine to 16 for a few days at least. If you test it every day and you see your chlorine start to stabilize (not drop fast from day to day) then you are in a good place and can drop your chlorine to normal levels.

You can work on your pH, CYA, and chlorine all in the same day, but you cannot add them at the same time! Make sure you give an hour in between with your pump running high that whole time. It is always best to add the chlorine after sundown to keep it from burning off right away, and actually having an effect on your water.

So... pH must be reasonable for a healthy environment. CYA must be 30-50 to keep your chlorine from disappearing. Get your chlorine to shock levels until you see it stabilize over a number of days, then bring it down to normal levels.

To make it much, much easier, get a good test kit (strips are nearly useless, and sometimes lead you in the wrong direction) and get the Pool Math app for your phone. But read Pool School as well for a real understanding. It will start to make sense quickly.

I hope things turn around quickly for you.

Peace,
Dave

Hey - ty for reply - am in Luzon - above Manila - 10 years now. Here is latest pic of ph and chlorine - adding 2kg of stablizer tonight to the pool - 20,000 gallons of water in it. Ph drops are so red I think PH is low - what do you think base don that101279
 

PoolGuyInPH

Active member
May 5, 2019
25
Philippinnes
The Taylor test kit -$135 USD - would that have everyting needed to test for 1 year or ? I live overseas so would buy each year when home and bring back if can last a year. Not sure how much chemical for drops comes with it =)
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
38,286
Tallahassee, FL
Please tell us which kit this is.............there are several different Taylor ones. The one you want is the 2006C the C is very important as it indicates it has more regents.
 
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