Does chlorine kill established black algae?

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poolbrush

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Jul 29, 2016
33
tulsa,oklahoma
I was reading the Taylor 2004b (instruction book that comes with K-2006 test kit) and it said that chlorine will not eliminate or kill black algae. The manger/owner(?) of the pool supply store in which I was reading this, echoed those same comments. So of course I bought some Black Algae Algaecide.

Additionally, he said to be sure to vacuum to waste any area where you have brushed.

Comments?
 
Chlorine kills algae. It will kill black algae but it is often difficult to get the chlorine to the black algae as it is most often embedded in the masonry surface.

Daily brushing with a stainless steel brush and constant exposure to chlorine will absolutely kill black algae.
 
All algae can be killed by chlorine. Black algae is more difficult to kill and requires tenacity on your part to get rid of it. You must brush it daily and keep the chlorine elevated. After brushing the pool scrub any spots you can reach with a chlorine tablet, using rubber gloves to protect your hands. Check the label on the algacide, it probably contains copper, which in high enough levels will stain your pool.
 
zea3 said:
All algae can be killed by chlorine. Black algae is more difficult to kill and requires tenacity on your part to get rid of it. You must brush it daily and keep the chlorine elevated. After brushing the pool scrub any spots you can reach with a chlorine tablet, using rubber gloves to protect your hands. Check the label on the algacide, it probably contains copper, which in high enough levels will stain your pool.
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I have already added the Black Algae Killer early this morning per the pool supply store recommendations. It does contain copper. (.27 lbs per gallon) and I added one qt, so about .06 lb.

This is really frustrating, and humbling. I got into this mess because of bad/ misunderstood guidance from a different store. ��

Can you describe the brushing process? I bought a 5" stainless brush to use. Do I bear down as hard as I can and how many strokes is considered adequate?

Thanks
 
You want to use firm pressure so you open up the "skin" of the algae so the chlorine can do its job. Give it a few strokes with the brush and it if looks like it took some of it off scrub it good with a chlorine tablet. You probably won't get all of the algae the first time and you don't want to scrape so hard you take all the plaster off. The pool school article in the post by pooldv has our recommendations for black algae removal.
 
zea3 said:
You want to use firm pressure so you open up the "skin" of the algae so the chlorine can do its job. Give it a few strokes with the brush and it if looks like it took some of it off scrub it good with a chlorine tablet. You probably won't get all of the algae the first time and you don't want to scrape so hard you take all the plaster off. The pool school article in the post by pooldv has our recommendations for black algae removal.
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I have read read the Black Algae removal article several times, however the example pictures won't display either on my iPad or my desktop PC.

When I brush I see a cloud surround the brush. Is that normal?

Here are my pool numbers just obtained with my new K-2006

CNA-52
FC- 11.5
CC-2
PH-7.1
 
It sounds like you have more pressing problems than black algae. Your description and your test results indicate a need to SLAM your pool.

You are missing CH and TA test results but you still need to SLAM, I think.

How does your water look?
 
duraleigh said:
It sounds like you have more pressing problems than black algae. Your description and your test results indicate a need to SLAM your pool.

You are missing CH and TA test results but you still need to SLAM, I think.

How does your water look?
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TA-140
CH-450

Water looks pretty good. Maybe slightly cloudy.


Additionally, I tried to scrape some of the black alage with my fingernail to sample on a rub on white paper, but could not get any under my finger nail. But I have brushed the areas several times already.

I will attempt to add a picture of my problem areas.
 

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image.jpgN

This is the only decent shot I could get. This is on the steps in shallow end. As you can tell, these aren't dime or quarter size patches. They seem to be large areas two to three feet in length and look like dark sediment, much like undissolved Shock lying on bottom.
 
I think you are dealing with an entirely different problem. Black algae literally looks like small black spots. What you have looks more like metal stains or calcium scale. Have you ever used copper or mineral based products? How long have you had these patches? Did you recently lower your pH?
 
zea3 said:
I think you are dealing with an entirely different problem. Black algae literally looks like small black spots. What you have looks more like metal stains or calcium scale. Have you ever used copper or mineral based products? How long have you had these patches? Did you recently lower your pH?
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The problem (whatever it is) manifested itself about a week ago after our chlorine level got real low to non-existent. This occurred due to a misunderstanding between my wife (the primary pool caretaker) and a person at a local pool store coupled with a gigantic amount of organic material in the pool after a huge wind storm.

We have never used copper based products to my knowledge, with the exception of me using a copper based Algaecide this morning at the direction of a different pool store person. I told him we had black algae because wife said we had black algae, and it does look black.

I am open for suggestions, because in short, I have no idea what I'm doing. But the endless stream of half-wits and lazy dullards that I paid for over the years surely are not smarting than I am. I'll figure it out. just gonna be painful getting there.

Thanks
 
Did the black stains happen when someone broadcast calcium hypochlorite into the pool?

Black algae is very slow growing. It does not appear over large areas very quickly.

Can you describe the events leading to the black stains?
 
JamesW said:
Did the black stains happen when someone broadcast calcium hypochlorite into the pool?

Black algae is very slow growing. It does not appear over large areas very quickly.

Can you describe the events leading to the black stains?
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I am not exactly sure as I was out of town, and my wife was at the controls when the black stains showed up. And now she is out of town (and not responding to my texts)
 
poolbrush said:
I am not exactly sure as I was out of town, and my wife was at the controls when the black stains showed up. And now she is out of town (and not responding to my texts)
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I think you need to check if you're passing FC overnight loss test. This is simple test- you measure your FC after sunset and before sunrise so the Sun doesn't get a chance to shine on your pool. If the difference is < 1 ppm you're good but judging by cloudiness of your water I suspect it won't be the case. Please don't add anything to the pool during the test and turn off SWG if you have one. The idea is to find out if anything is consuming your FC in the pool. Just for water clarity reference- TFP water doesn't diffuse light beam from pool light :).
 
Good morning to everyone,

I believe the black stains are copper stains, not black algae. Two words: pristine blue. Chief of Staff starting using that product line unbeknownst to me and the day after she added "lithium something" the stains showed up.

Here are my numbers from this morning:

FC- 4.8
CC- 0.6
PH-<7.0 (tested several times)
CYA- 90-100
TA- 110
CH-350 (tested several times)

I tested my FC last night at sundown, it was 9. This mornings test was after sunrise but before and direct sunlight hit the pool due to tree shade. Something is eating my chlorine.

Standing by further instruction. In the meantime, I will dig out my sump pump, as I don't have a main drain and I think a water replacement is in my future.

Thanks
 
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