Bleach

Algae problems in swimming pool water.
Green (cloudy) water or slimy pool walls.
Black algae. Mustard algae. Pink or white pool mold.
chem geek
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Postby chem geek » Sun 09 Mar, 2008 20:27

The 1 gallon of bleach per 1,000 gallons, if the bleach were Clorox Regular or an off-brand Ultra at 6% concentration, would raise the FC to nearly 62 ppm so would be WAY too high. You are correct that it probably should have been 1 gallon of bleach per 10,000 gallons which would raise the FC by 6.2 ppm which is far more reasonable (assuming there is some CYA in the water).

Also, it is not true that bleach or chlorinating liquid will raise the pH permanently. It does raise it upon initial addition, but the usage of chlorine from breakdown from sunlight and oxidation of ammonia/urea and organics is an acidic process that exactly compensates for the pH rise (except for a SMALL rise from excess lye). Technical details of this may be found here.

If the pH rises when using bleach or chlorinating liquid on an ongoing basis, then it is due to outgassing of carbon dioxide (pools are intentionally over-carbonated to provide a pH buffer and prevent dissolving of plaster) and the solution is to lower the TA level which reduces the tendency of the pH to rise. I only use 12.5% chlorinating liquid in my own pool (no other chemicals) and my pH is rock solid over time. I also have an opaque electric safety cover so the outgassing of carbon dioxide is minimized (and I keep my TA at 80). Even with use 5 days a week, I only need to add chlorine twice a week as it only uses around 1 ppm FC per day (since the opaque cover keeps out the UV rays of the sun when the cover is closed).

Richard


slprncess

Bleach

Postby slprncess » Sat 24 May, 2008 20:13

I have posted another post about algae in my pool and I am trying to get rid of. I have purchased new system 3 filters and am wondering how i should tackle this. Should I drain or try to clear up with the new filters and chlorine or bleach? I have read that bleach is much less expensive then liquid chlorine. How much bleach should I use to clear up my pool? It is between 15-25,000 gallons. Sorry havent exactly measured. I really dont know how to measure. This is just a assumption.

Please help!!
chem geek
Pool Industry Leader
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Posts: 2381
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Bleach

Postby chem geek » Sun 25 May, 2008 05:42

Use The Pool Calculator to figure out how much chlorine to add. Chlorinating liquid is not always that much more expensive than bleach. First of all, you should only be looking at bleach that says its concentration such as 6% for Clorox Regular or off-brand Ultra (off-brand Regular is sometimes 3% or less). Second, realize that 12.5% chlorinating liquid at $3.65 per gallon (the price I pay for what I use) is equivalent to $1.35 per 96-ounce (3/4 gallon) jug of bleach.
slprncess

Bleach

Postby slprncess » Sun 25 May, 2008 15:07

chem geek wrote:Use The Pool Calculator to figure out how much chlorine to add. Chlorinating liquid is not always that much more expensive than bleach. First of all, you should only be looking at bleach that says its concentration such as 6% for Clorox Regular or off-brand Ultra (off-brand Regular is sometimes 3% or less). Second, realize that 12.5% chlorinating liquid at $3.65 per gallon (the price I pay for what I use) is equivalent to $1.35 per 96-ounce (3/4 gallon) jug of bleach.


Would you suggest just trying to clear up with chlorine or should i drain if it is that bad? i dont want to spend all this money on chlorine for it to do nothing!
sqompy

pool turning green already

Postby sqompy » Wed 16 Jul, 2008 08:37

I have just replaced my liner and started filling my pool (27Ft round). It is not even half full and already has a tint of green. This happens every year no matter what I do the darn thing turns green. The pool place just keeps telling me to use the shock (granules) and it does nothing. Should I try to put bleach in the pool now before it gets any worse? How much bleach should I put in 18,400 gal water?
Guest

Bleach

Postby Guest » Wed 16 Jul, 2008 15:08

In order to give advice on any pool you have to know the chemical balance of the water.

I would get your fill water tested to see what chemical levels you have. From there you can get advice on what to add.

In general, you will need chlorine. Most forms of chlorine will add other products to the water. If you need those extra products then it could be a good form of chlorine to use. Until you have a full set of chemical balance numbers you can't tell what would be best.
thinkpool

Green Algae (Mustard)

Postby thinkpool » Mon 18 Aug, 2008 08:00

:(
I have serious green algae problem. All the values tested are within range. I used pool calculator to figure out the amount Bleach needed. But, the result was ineffective. FC= 2-5 Ph~ 7.5, so I added 2.7 gals of Chlorox in the night and same color "mustard green" next morning. Test again, FC= 7-8 Ph~7.8. Do I continue with Chlorox treatment? :?:
Thanks in advance for any advise!!!
chem geek
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Bleach

Postby chem geek » Mon 18 Aug, 2008 11:18

"all the values are in range" is not a complete set of test results. What is the Cyanuric Acid (CYA) level? Also, has the water been tested for copper or is the water a "clear green" as opposed to cloudy or looking like algae. You should really get your own test kit. You can get the Taylor K-2006 kit at a good online price here or you can get the TF100 kit from tftestkits(dot)com here with the latter kit having 36% more volume of reagents so is comparably priced "per test".
thinkpool

Bleach

Postby thinkpool » Mon 18 Aug, 2008 11:33

Thanks. CYA= 150 and cloudy mustard green. I think "mustard green" means copper present. :D :?
chem geek
Pool Industry Leader
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Posts: 2381
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Bleach

Postby chem geek » Mon 18 Aug, 2008 13:34

150 ppm CYA is way too high. To prevent algae growth in a manually dosed pool, you would need to keep a minimum Free Chlorine (FC) level of at least 11 ppm and I doubt you were doing that. You need to do a partial drain/refill to get your CYA lowered. You should also consider switching from using Trichlor to using chlorinating liquid or unscented bleach for at least part of your chlorine needs. For every 10 ppm FC added by Trichlor, it also increases CYA by 6 ppm so unless you have a lot of splash-out, a small pool, and a filter that is backwashed weekly, you can end up having the CYA rise in just one or two seasons.

You can learn more about pool water chemistry and properly managing a pool at Pool School.
thinkpool

algae

Postby thinkpool » Mon 18 Aug, 2008 17:06

:oops: Sorry, CYA=150 based on the test kit indicating that "black dot" starting to disappear...
So, I went to the pool place for water sample test, and the result showed CYA=25 (they say the "black dot" indicator should disappear); they use a stick with level indicator to measure CYA.

Pool place recommendation:
10.5 lbs of Balance Pak 100
1.5 lbs Lo & Slo
3 lbs of Stabilizer
4 bags of Burnout
1 bottle of Banish
chem geek
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Posts: 2381
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Location: San Rafael, California

Algae

Postby chem geek » Mon 18 Aug, 2008 17:19

Did you use a Taylor test kit for testing CYA and did you use the readings on the back of the tube as shown here? Did the CYA test proceed as shown in this link? If you added a lot of liquid before the black dot disappeared, then the CYA level is low and the pool store is correct. How did you get to a measurement of 150 when you did the test?

If the CYA is low as the pool store indicates, then if your FC is high and the green persists, then it is more likely to be copper, especially if it's a clear green. Try lowering the pH. If the green gets more clear, then this is very likely to be copper and adding a metal sequestrant when you are at low pH will help though over time you're going to have to replace your water through periodic dilution (partial drain/refill). To make sure that this is what you've got, have the pool store test for copper. Did they do that?

Balance Pak 100 is identical to Arm & Hammer Baking Soda. You didn't say the size of your pool, but 10.5 pounds in 15,000 gallons would raise the TA by 50 ppm which is a lot. You didn't say what your TA level was. In fact, you didn't explicitly list any of your levels which makes it very hard to tell you what to do. I would NOT trust the pool store with their numbers -- very often they are wrong.

Lo & Slo is Sodium Bisulfate which is aka dry acid and will lower pH. You can use Muriatic Acid you can get at a hardware store instead and won't add sulfates to the water. The 1.5 pounds in 15,000 gallons would lower pH from around 7.6 to 7.4.

3 pounds of stabilizer in 15,000 gallons would raise the CYA by 24 ppm.

BioGuard BurnOut is lithium hypochlorite which is the most expensive form of chlorine there is. Bleach or chlorinating liquid is FAR less expensive and accomplishes exactly the same thing -- it's just heavier to carry since it's mostly water.

Banish is a copper-based algaecide so if you've got copper in your pool already it's definitely not the thing you want to use and even if you don't already have copper you can stain your pool by adding it. Do NOT use this algaecide.

For clearing a pool of algae, read this link from The Pool School I linked to earlier. However, it's still not clear whether you have algae or not -- are you sure it is algae? Is the water dull/cloudy green or is it a clear green? You said it was mustard green which is a color, but didn't describe the clarity of the water.

Again, I strongly encourage you to get your own good test kit and take control of your water; otherwise, you will be at the mercy of the pool store and will spend a lot of money on your pool which may or may not work at helping you, depending on the competency of the pool store. The only test I would have the pool store do is to test for metals (copper, iron).

By the way, 2.7 gallons of unscented Clorox Regular 6% bleach in 15,000 gallons would be 11 ppm FC which isn't very high for fighting algae if the CYA is high and even if the CYA is low you need to keep adding chlorine to keep the FC up. If algae is present, it will consume chlorine quickly so you need to keep testing FC and adding more. With the test kits I linked earlier, you can test high chlorine levels easily up to 50 ppm. With regular chlorine test kits, you cannot easily test above 5 ppm FC.

Richard
thinkpool

algae

Postby thinkpool » Mon 18 Aug, 2008 17:47

Thanks for responding so quickly... really appreciated your expertise..
The way I tested CYA (HTH test kit), I stopped at midpoint as you showed pictorially, which was my misunderstanding of "starting to disappear" and guesstimated since its half way to "100".

Pool looked "mustard green and cloudy"; however, water showed just slightly cloudy in test bottle.

Unfortunately, the pool place unable to print due to printer mulfunction.
Pool place said I have zero chlorine, TA low, pH=7.8 and CYA = 25; and, recommended the chemicals to add.
10.5 lbs of Balance Pak 100
1.5 lbs Lo & Slo
3 lbs of Stabilizer
4 bags of Burnout
1 bottle of Banish

I looked at your CYA/FC chart and followed the amount FC needed is 12.7 ppm. So, based on Pool Calculator I need 4 gals of bleach (6%).
Do I need to bring up TA before adding bleach?

I am not sure if I missed any info you needed.
Thanks in advance for your advse.
Guest

Re: algae

Postby Guest » Mon 18 Aug, 2008 18:43

[quote="thinkpool"]Thanks for responding so quickly... really appreciated your expertise..
The way I tested CYA (HTH test kit), I stopped at midpoint as you showed pictorially, which was my misunderstanding of "starting to disappear" and guesstimated since its half way to "100".

Pool looked "mustard green and cloudy"; however, water showed just slightly cloudy in test bottle.

Unfortunately, the pool place unable to print due to printer mulfunction.
Pool place said I have zero chlorine, TA low, pH=7.8 and CYA = 25; and, recommended the chemicals to add.
10.5 lbs of Balance Pak 100
1.5 lbs Lo & Slo
3 lbs of Stabilizer
4 bags of Burnout
1 bottle of Banish

I looked at your CYA/FC chart and followed the amount FC needed is 12.7 ppm. So, based on Pool Calculator I need 4 gals of bleach (6%).
Do I need to bring up TA before adding bleach?

I am not sure if I missed any info you needed.
Thanks in advance for your advse.[/quote]

water volum = 19.8 k gals (16x30 in ground pool)
chem geek
Pool Industry Leader
Pool Industry Leader
Posts: 2381
Joined: Thu 21 Jun, 2007 21:27
Location: San Rafael, California

Algae

Postby chem geek » Mon 18 Aug, 2008 19:22

I can't say whether you need more TA since "low" doesn't mean very much. I suppose it wouldn't hurt to add half of what they said, so 5 pounds of Arm & Hammer Baking Soda (unless you don't mind spending more for the Balance Pak 100). It's easy to raise the TA, but harder to lower it.

If I were you, I'd redo your CYA test in your HTH kit but read it now that you know what to look for. If the CYA were really 25, then it will go all the way up to the top of the tube and you'll still barely see the black dot since the top of the tube is near 30 ppm CYA.

If your CYA is really that low, then I'd just target 15 ppm FC, but the key is to keep adding chlorine every hour or so if the FC drops. Also, brush the pool to get the algae circulating with the chlorine. You may need to clean your filter if the pressure goes up when it clears dead algae. Your pool should go from green to gray (or aqua-gray or pale-green-gray) if you are doing things correctly. See this link for how a pool with lots of algae upon spring opening gets cleared using chlorine alone.

Richard

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