How long should it take to clear black algae

[Watermom]

You should be multiplying that result by 7 which would be 14. Read the guide at the following link:

http://www.poolsolutions.com/gd/how-...d-testkit.html

Since your CYA is 60, you should be shocking up to 20. So, you need to go a little higher with your chlorine. You're not quite getting it to the point to do the job. In your pool, each gallon of 6% bleach will add 5ppm to the water. When you test 3x per day, are you adding enough bleach to get back to 20? If not, start doing so.

Regarding CC --- you WANT it to be 0.

[joecus]

Sorry, I wrote the wrong computation, I am multiplying by 7 and getting 14. Normally I take 3 parts water and multiply by 4. Today I did 6-1 and used a calculator and messed it up, So My number is 14, not 33. I will raise it up to at least 20 for the next three days and see what happens.

[Watermom]

OK. Try and sustain that high reading without letting it fall. I know that is not totally possible, but the more often you can add bleach and get back up to 20, the better.

[joecus]

Hello all - I'm still having the same problem. At night, I bring my cl up to 40 or above, by morning it's about 20. I then bring it back up to 40, by 2 pm it drops to about 20, I bring it back up to 40, by 8pm I'm back to 20. This has been going on for at least 1 week. I'm using 10 - 12 gallons of bleach everyday. I added the bioguard algae 60, 5 days ago and yesterday. Is there anything else I can do? No one has been in the pool this week. When I see the algae I brush it off. Any help would really be appreciated. Joe

[Watermom]

By any chance do you know what your CYA level was upon closing in the fall?

Read the article at the following link: IF you had CYA upon closing and either none upon opening or much less than you had, this may be what is going on with your pool.

http://www.poolsolutions.com/gd/spri...-problems.html

If I'm right, we've seen this MANY times before, this year and in previous years. You think you're never gonna get to the end of the cycle and then one day, you do!

The "black algae" that you are brushing up may just be dirt. I have a pad under my liner that is taped together. When the liner was installed, I can still see the lines under the liner where it was taped. In my pool, dirt settles in these lines. I can vacuum one day and then the next day, the dirt has again collected in the lines. We swim and it gets stirred up but it is a continuing cycle. Maybe that is also what is happening to your pool as far as the black stuff and your chlorine demand is not due to algae but due to high levels of ammonia as the article above talks about. Just wondering .........

[Yeggim]

Hello all - I'm still having the same problem. At night, I bring my cl up to 40 or above, by morning it's about 20. I then bring it back up to 40, by 2 pm it drops to about 20, I bring it back up to 40, by 8pm I'm back to 20. This has been going on for at least 1 week. I'm using 10 - 12 gallons of bleach everyday. I added the bioguard algae 60, 5 days ago and yesterday. Is there anything else I can do? No one has been in the pool this week. When I see the algae I brush it off. Any help would really be appreciated. Joe

Couple questions for you. Correct me if I'm wrong. You're using an OTO Chorine test--no?

1. How are you getting your CC results?

1. Is this black stain slimy to the touch?

[joecus]

Watermom - Great article. I did have a high CYA last year 100+. I did 3 partial drain and refills to get it down to current levels of about 70.

As far as my CC levels, I am taking 30 part tap water to 1 part pool water. I come up with a range of .5 to 2 on the scale of both my test kits. I then multiply by 31. Last night, I put cl levels up to 60+ this morning it was about 40. I am going to test right now.

I'm pretty sure my black spots are algae. Two weeks ago, I had trouble brushing them away (would not move). Now, it appears to be dead and are easily brushed off. The are mostly on the corners, and around my underwater pool light. It seams to like to form there but it does also sometimes form on bottom. I haven't touched it with my hand recently, but a few weeks ago it did not feel slimy to the touch and would not scrub off easily. Like I said, the pool is very clear, rarely used, 0 times since last Wednesday. Next week school is out and it will get much more use. Thanks, I will post complete set of numbers in an hour.

[PoolDoc]

It's not gone. Once you have black algae, it's rarely gone, unless you've drained, pressure washed, and resurfaced. It gets in, and under the plaster (see picture series below). You can kill the bits that are exposed, but not the bits that aren't.

You have to maintain levels of chlorine that prohibit further growth, because it tends to re-emerge the first time you give it a chance.



3/4" glass tiles to the right.


3/4" glass tiles above

[joecus]

Hello all, sorry it took so long to post. Here's where the pool is;
Last night my cl was 70 ppm.
cc = 70 ppm
This morning its 30 ppm.
ph = steady at 7.6
cya = 30-50 on aquacheck strips. I ran out of the cya testing drops - r0013.
The CL has not been under 20 in 5 days.

Pooldoc - my pool is an in 12,000 gallon, in ground liner pool. I assume this algae can be defeated, can it?
Watermom - I've been using less bleach the last few days 6-8 gallons. I've been going real high at night, 60-70. Checking it 4 times a day. I'm not sure if the reduction in bleach needed is due to my pool getting better or just the weather (it's been very cloudy the last few days). Please let me know what you think. Also, can anyone advise me where to best place is to get refills for the Taylor kit? What is the normal amount of cl burned during a sunny day? Thank you very much for your help.

[PoolDoc]

Controlled, not defeated.

Think of it as "cancer", and that with proper treatment (adequate chlorine levels ALL the time) you can keep your pool in remission.

Ben

PS. The only reliable way I know of "defeating it" means a new surface -- either plaster or epoxy paint.