CYA Problem URGENT

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Either will work, the 28 will work faster, that's all.

So the Pool party explains the urgency....

I'd say that's up to you - if you have high CC level it could be irritating to some, but at this point what else can you do? Shock and tell everyone not to get in? :mrgreen: I'd keep the levels elevated during the party, and then shock before you go to bed. Same thing tomorrow.

To answer your prior questions, Richard basically answered them up above. No, you don't want to use sodium percarbonate in a chlorine pool, yes, MPS does kill some organics but not as fast as chlorine, the first one, I'm not sure but it won't stop you from having a pool party right? :cheers:

Have fun!
 
- so in that case i just elevate my Cl to a FCL 14 ppm and then raise to FCL 20 -28 ppm after the parties.
- the FCL of 14 ppm shouldnt stink the users right?
- Haha everyones invited if you dare take a swim. :-D
 
I knew what you meant, yes, a FC of 14 is fine with your current CYA, which is 70, correct?

Hong Kong! Wow...I figured you were somewhere far when you said "party today" and today is just about over where I am..... Have a great party.... :wave:
 
aho.lwi said:
Thanks for the help guys.

Last Few Question:

- Since MPS and Hydrogen peroxide are both oxygen releasing why does one destroy Cl and the
other doesnt?
- So in other words MPS does kill algae just that it isnt fast like Cl?
- So in other sodium percarbonate is no good for a Cl pool as well?
Click to expand...
(I sort of answered this already, but will be more specific to your questions)

Because hydrogen peroxide is not only an oxidizer, but is also a reducing agent -- it can go either way. So the chlorine oxidizes hydrogen peroxide (or equivalently the hydrogen peroxide reduces the chlorine). MPS is only an oxidizer so does not react with chlorine.

Yes, MPS does oxidize dead algae, but it's not designed for killing live algae so shouldn't be used for that purpose. I'm not even sure how much you would have to use to try and kill algae faster than it could grow if you had an algae bloom. We know how much chlorine is needed, both for shocking for a faster kill and for maintenance to prevent algae growth.

You are correct that sodium percarbonate is also not good for a chlorine pool since sodium percarbonate in water produces sodium carbonate (pH Up) and hydrogen peroxide (so see above for what happens with chlorine and hydrogen peroxide).

Richard
 
Thanks guys, valuable lesson learnt ill keep you posted and see how things go:

Basically im thinking of raising my FCL to 14ppm and maintain for a day or two
and add a good 2 - 3 kilos of MPS on the way any suggestions?

SHouldnt harm the swimmers right?
 
aho.lwi said:
Thanks guys, valuable lesson learnt ill keep you posted and see how things go:

Basically im thinking of raising my FCL to 14ppm and maintain for a day or two
and add a good 2 - 3 kilos of MPS on the way any suggestions?SHouldnt harm the swimmers right?
Click to expand...

You DON'T need the MPS and it will just show up on your tests as CC's. Your cloudy water was likely the start of algae and the MPS won't really help that anyway. Just stick with the chlorine, all will be fine.
 
Tried shocking my 25,000 gallon pool with 3 kilos of Cal Hypo 65% FCL was 4 ppm next day i was registering Cl 0.4ppm. I then went to add another 15 kilos of Cal Hypo 65% to shock my pool, friends came and used my pool commenting that coating of a powdery substance in their gums and that they felt a really strong chlorine taste.

Water is still cloudy after treatment, what have i done wrong? And how do i treat this problem which my friends commented about? Is there a quick fix to this? ANd in the future what procedures should i follow before i go dosing?

Iv tried following the chart for algae treatment but i guess there is something i might be missing?

Test Results:
pH : Lower than 6.8
TA: 10 ppm
FCL: 25 ppm
CAL: 120
CYA: 50
Temp: 28C
 
How did the pH get so low? If you are using Cal-Hypo and not Trichlor for chlorine, then the pH should not have gotten so low (unless you added acid at some point). A pH that is very low can harm equipment (corrode metal) and if anyone was swimming in such water it can sting the eyes. Also, are you sure the Total Alkalinity (TA) is only 10 ppm (i.e. 1 drop go to from green to red in a drop-based TA test)?

In your first post in this thread, you said the pH was 7.5, TA was 80, CH was 140 and CYA was 70. Now you say that the pH is <6.8, TA is 10, CH is 120, CYA is 50. The CH and CYA numbers are reasonably consistent (within test error) and could be lower due to some dilution of the water. However, what in the heck did you do that got the pH and TA so low? You mentioned you had MPS -- did you add a lot of this? MPS can be acidic, though it's not strongly so. It could lower the pH probably to around 7.2 or so, but the TA would only drop by around 6 ppm or so. I don't understand how yours went from 80 down to 10 and why your pH got so low. At high FC levels the pH test won't be accurate, but would tend to measure falsely high, not low. What did you add to your pool besides chlorine?

At shock level of chlorine, people would taste the chlorine so that's to be expected and at normal chlorine levels this won't be very noticeable. It's the low pH and very low TA that are most puzzling.
 

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I guess i added a bit too much of sodium bisulphite, wanted to make sure that the Cl was working at 100% efficiency.

What can i do to remedy the situation? Iv got friends complaining of powdery substances building on the gums and now my kids want to swim....

Am i actually on the right track on killing my algae? And whats a safe level of Cl, or what Cl levels are undetectable?

Basically all i did was adding Cal Hypo, SOdium Bisulphite and a couple of backwashes.... can you guide me...? What next?
 
Basically my water is cloudy and ppl are complaining? Iv tried tackling this pool and a bit fed up... havent had much luck in the last 3 days.

Iv switched my feed tank off, i hope the high Cl lvls and couldiness will dissapate in a days time.

Can high Cl levels cause cloudiness?
 
You should not have lowered the PH. That just made everything worse, and could have caused some damage to your pool depending on just how low the PH actually is. You need to keep your PH between 7.2 and 7.8. Whatever you think "wanted to make sure that the Cl was working at 100% efficiency" means is wrong. The PH should be kept between 7.2 and 7.8 and chlorine is very effective in that PH range.

Have you done an overnight FC loss test? What are your recent FC readings?
 
Going to be doing the test tonight, besides i see bucket test being talked alot about when should i be doing this?

Whats witht he powdery susbtance that my friends were feeling on the gums?
 
High chlorine levels don't cause cloudiness.

You have had the cloudy water because...either you haven't gotten ahead of the algae problem, and the algae is consuming the chlorine as you add it, or.... the algae is dead and the filter just needs a chance to clear it, or something is wrong with the filtration system. You need some POP - Pool Owner Patience. Dumping a bunch of different chemicals in the pool could cause more harm then good. You just need chlorine, and adding it properly.

Cal-hypo can cause temporary cloudiness. What made you decide to use cal-hypo? Is your pool plaster or vinyl?

Come to think of it, can you put all your pool specs in your signature....type of pool, size, kind of filter, etc.

How often are you running your pump/filter?

First confirm an overnight FC loss test. If you lose more than 1ppm you need to follow the instructions in How to Shock your Pool and use liquid chlorine if you have access to it.

Shocking means keeping your FC up to shock level with frequent chlorine additions until the FC holds overnight and your CC is .5 or less.

Do you have access to clorox type-bleach 6% or liquid chlorine 10-12.5%?

Now that your CYA is 50, your shock level is 20 FC.

Fix your PH and TA levels asap...before you begin shocking.

The powdery feeling could have been from swimming with undissolved powder from using cal-hypo? Who knows...

When you say "feed tank" what does this mean?
 
aho.lwi said:
I guess i added a bit too much of sodium bisulphite, wanted to make sure that the Cl was working at 100% efficiency.
Click to expand...
To go from a TA of 80 to 10, you would have had to have added about 30 pounds of sodium bisulfate to your 20,000 gallon pool! How much did you add? As was pointed out, that was not necessary at all, and certainly not in that quantity. If you didn't add that much, then perhaps your testing is in error (either the first results in this thread or the most recent ones).

If your most recent results are accurate, then adding 21 cup of pH Up (Arm & Hammer Super Washing Soda) would get your TA back up to 80 and you could aerate the water to get the pH higher as well. I would add half of this amount and then retest, just to be on the safe side since you don't want to overdose again. However, I'm highly suspect since I doubt you added 30 pounds of sodium bisulfate to your pool, right?
 
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