How long should it take to clear black algae

Hello all - I need some help. I can't keep my CL levals above 10 for any length of time. Here are my numbers

fc = 2
tc = 3
ta = 90
cya = 70
ph 7.6

Every night I've been adding 2 gallons of bleach which raised my cl to about 20. Next morning, my numbers are about levels I posted above. I do have black lines near steps and corners which I assume is algae. How high and how long do I need to keep my cl levels to kill this thing. I've been using many gallons of bleach, yet no progress. Also, how high of a level is safe for swimming? Thanks a million.

One more question, I have a stand alone hot tub. My alk levels are low. All others good. How can I raise Alk only? Thanks again.

OK, you are on the right track. You want to raise and keep your FC at 20. You need to test and raise FC at least 3x/day.

Meanwhile you need to brush your pool every day to knock the algae loose, and you should vacuum the pool every day as well, preferably to waste, until it's clear.

I think what's happening is the algae is using up the chlorine and you aren't getting more chlorine in the pool fast enough to prevent the algae from growing back.

Carl

With your CYA at 70, I wouldn't have a problem swimming with chlorine in the 10-15 ppmrange, but I'd probably wear an old suit.

To raise alk, use baking soda.

Janet

yep, with CYA 70, it takes a high shock level, especially with black and/or mustard algae (I think mustard is worse!)
You need to maintain the shock level as consistently as possible- during the day, as Carl said, the FC drops low enough to let the algae grow back.
add more bleach in the AM, to get the FC back up, and whenever you can during the day test and raise FC again.
As aylad said, you can swim at higher levels, even 20-25, with that level of CYA; but might be harsh on swimsuits!
You need to maintain these FC levels until your pool holds FC overnight- lose no more than 1ppm FC between sundown and sunup, without adding more chlorine!

Hello all, I've been keeping the CL very high yet I'm not seeing progress. How long can I expect this to last? What about raising the CL really high, (50-60 no swimming) will that resolve my problem faster>

not sure if I'd go that high- but super shock level is 75 for your CYA range, so it should be ok- maybe Ben or someone else will be in later to advise you...

Madwil -- your post doesn't make any sense. He is wondering about taking the cl really high -- up to 50-60. You tell him you're not sure if you would go that high, but 75 should be ok.

joecus --- I did not see (unless I missed it) where you told if this was a liner pool. But, do NOT take the cl up to 75 unless Ben recommends that you do.

Are you consistently keeping the cl at shock level? If not, letting it yo-yo up and down will make it take forever and a day to clear. Are you brushing the sides and floor?

Go ahead and post another set of numbers since it has been a couple of days since you have done so. Are you running the pump 24/7? Is your filter pressure rising? How does the water look?

my post wasn't supposed to make sense- why I stated that hopefully someone else would come in to advise; I wouldn't want to go to 50, but the supershock says to... if Ben told me to, I'd probably do it, but would sit on nails waiting for results!

Weird, since I have no issue at 30-40 ppm chlorine, I guess 50 is just my "shutdown" number...

Hello all, I've been checking 3 times a day and adding bleach when necessary. It comes to about 2 gallons a day. My pool is 12k gallons. My numbers right now are as follows:
fc = 33
tc = 33
cc = 0
cya = 60
ph = 7.8

Let me review my formula with the group to make sure I'm doing it correctly. I'm taking 6 parts tap water to 1 part pool water. I get a cl level of 2. 1/6 * 2 = .33. The ph and cya are done with pool water only. It's been varying from 33 at night to 15 in morning. Any ideas? Water is crystal clear. What is the significance of zero CC? Thanks for any help, I really appreciate it.

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.

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.

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.

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

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 .........

Quote:

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Originally Posted by 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

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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?

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.

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.

https://lh3.googleusercontent.com/-I...CP00376-ed.jpg

3/4" glass tiles to the right.
https://lh3.googleusercontent.com/-k...CP00381-ed.jpg

3/4" glass tiles above
https://lh4.googleusercontent.com/-6...CP00442-ed.jpg

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.

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.

Quote:

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Originally Posted by joecus

Also, can anyone advise me where to best place is to get refills for the Taylor kit?

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I get mine from spspoolspas.com. They can also be ordered from Amato industries online, or the taylortechnologies.com

Janet

Pooldoc - I'm not sure if you caught that I have a liner pool. Does that change anything? Any idea of how much bleach I should use on a normal day (no algae).

Joe,
Ben probably did miss that part. He's out of pocket for a bit, so it may be a couple of days before he is able to get back to this thread.

A couple of questions for you? What kind of kit are you using? You cannot use the dilution method for extended periods of time, especially when you are going to really high levels like you seem to be doing.

I'm concerned what you may be doing to your liner with these kinds of high chlorine levels. Are we sure it is black algae?

Check that and maintain your chlorine levels for now until Ben is able to get back to you on this thread.

The way Ben suggests to check to see if it really is black algae is to scrape some off, and under your fingernail. Then, dry off, and smear the stuff under your fingernail onto a white index card. If the smear is green -- you have 'black' algae. Maybe you can try that to verify if it is indeed black algae.

I think we may have suggested it before up in this thread (don't have time right now to reread the entire thread) but in case we didn't, you need to get a good kit! (Amazon link below.)

-- Momentarily camping out in the cabin owner's office --

I did miss the liner bit; if it is black algae, you can eradicate it from a liner pool. But . . . you must get all of it, and you should try the "shmear' test Watermom described to verify that that's what you actually have. In liner pools, plasticizer bleeding can look like black algae, but algaecides won't help at all.

Ben

OK, I will do that. Any other suggestions, ph? Something is burning a lot of chlorine. What, other than algae, can do this? Should I switch back to tablets? Like I said, I'm using gallons and gallons of bleach. Thanks for your help.

Don't switch back to tablets. They have CYA in them and you do not want that any higher. If you can find someplace that sells liquid chlorine at a higher concentration, that would be fewer jugs to contend with. (Some places sell 10 or 12.5% sodium hypochlorite. Bleach is 6% sodium hypochlorite.)

I'm not sure what your question is about pH. Yours is fine at 7.6.

Stay the course. Test and add bleach every few hours if you can. No such thing as too often when fighting algae. Report results from the "smear" test.

Thanks, I will continue to add the bleach. I am really at a loss. Is there anything other than an algae that could cause this?

High ammonia from something that was added to the pool or from the biodegradation of CYA over the winter, neither of which apply to your situation. I know it is frustrating, but keep adding bleach.

Today, is sunny and I'm back to adding tons of bleach. My test kit is the Taylor one recommended here. I do want to switch to a higher bleach content. Is there any online store you use to order 10 or 12%? Also, please explain how much of the 32oz would = 128oz of the 5.5. It sounds like two quarts = 1 gallon but not sure. As far as the inconvenience 0f gallons, it's not a big deal. It's actually funny the comments I get from the cashier when they see me buying all their bleach. I pay $1.47 per gallon. How does compare to your price?

Quote:

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Originally Posted by joecus

Today, is sunny and I'm back to adding tons of bleach. My test kit is the Taylor one recommended here. I do want to switch to a higher bleach content. Is there any online store you use to order 10 or 12%? Also, please explain how much of the 32oz would = 128oz of the 5.5. It sounds like two quarts = 1 gallon but not sure. As far as the inconvenience 0f gallons, it's not a big deal. It's actually funny the comments I get from the cashier when they see me buying all their bleach. I pay $1.47 per gallon. How does compare to your price?

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Shipping costs would negate any savings over your current price, which is actually very good if it's 6%. A 5 gallon container of 12.5% weighs 40+ pounds. Is your bleach marked 5.5%? Even at 5.5%, a $1.47 a gallon is good. Are you sure it's a gallon? I don't see gallon jugs around here anymore. They're either 96 oz jugs or the 182 oz jugs.

Yes it is 1 gallon. It's a store brand (pathmark). It does not give the % on the label. I've tried to look up the % on the web without any luck. The directions match Clorox so I'm assuming it's 5.5. I've just ordered an ammonia test kit to see it that's my problem. Just a long shot chance. Last year I did have a major issue with one of the algaecide. The product name was United Chemicals Black Treat 3. It was a very weird problem, after adding this product, whenever I added chlorine, it would turn the water light green. By morning it was back to crystal clear. The water tested positive for metal. I bought a magnet/powder from my local pool store and mixed it with the earth. I did this along with few partial refills and the problem went a way. I'm thinking this may be some sort of residual from that problem. Any thoughts on partial doing partial refills. I have not been able to confirm the algae (smear test) due to me scrubbing it away on Saturday. I cannot see an algae present right now. One thing I have not been doing is running the filter 24/7. I reread the article Watermom put up and they suggested running 24.7 I am going to start doing this today.

I have a new development. I can't believe what going on. As I told you, my kit ran out of r0013. My last reading, two weeks ago, was 70. Last week I was using the strips and it dropped to normal on the strips 30-50. Today, I used the strip and it's showing zero. Now, I really need help. Please let me know what you think. Thanks very much.

Stick with the reading you got with the R0013 reagent with the black dot tube. Did you order more R0013 reagent?

Yes I did, today. I also went to Petsmart and bought an ammonia kit, pool measured zero. Here are my latest numbers.
CL = 9
PH = 7.2
I'm going to test first thing in morning. I will re-post then.

Yeggim - The water is crystal clear. I have very good news. My CL levels held very steady over night. Last night, CL=9. This morning it looks like 8 or 9. I feel much better than yesterday with regards to the pool. I was very worried the pool had an ammonia problem. As I said, that test came back negative. My CYA - is unknown due to the fact that I ran out of r0013. The strips have been showing a wide range so I'm sticking with my last "known" CYA of 70. So what is my target now with regards to the CL levels? Thank you for your help. One more thing, I would like to make a donation to the site. How can I do this?

Thank you, Yeggim for supplying the needed links for this member.

Joecus --- thank you for your interest in making a donation to the Forum. It will be most appreciated!

Glad to hear of the overnight results. That is good news!

Hello all, I'm not sure if this is normal so here is my question. I am no longer using chlorine at night, very steady. During the day, my CL goes from 10 down to .5 or 0. Any thoughts why?

Also, how long do you guys run your filter under normal conditions? Just let me know how many times water should filter and I will do the calculation based on my filter. I appreciate your time, Thank you.

Watermom, My spa is 540 gallons and has a bromine cartridge. Your point still applies. The bromine cartridge are very expensive but I guess I will stick with this system. It works pretty good but I was thinking about saving a few bucks. I've read that you can easily change from CL to BR without any issues, but cannot do BR to CL. I don't understand why, but that seems to be the consensus. So, I'm going to get the ph up to normal levels, stabilizer up to 10, then switch to the bromine. I know this is not your area of expertise but please let me know if my plan sounds plausible.

Quote:

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Originally Posted by joecus

Hello all, I'm not sure if this is normal so here is my question. I am no longer using chlorine at night, very steady. During the day, my CL goes from 10 down to .5 or 0. Any thoughts why?

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This is characteristic of low CYA *or* added bromines.

Thanks Burfle,

Please help. As some of you know, I ran out of taylor r0013. I am no longer losing cl at night. During the day, cl goes to zero. Here's my Here is my dilemma, The strips show my cya at zero. My last known reading with the Taylor kit was about 70. I believe my stabilizer is gone. I have 40 lbs 3" tabs on hand. I have a box of Pace Clear shock treatment, (99% sodium dichloride) and about 2 pounds of “chlorine stabilizer (2,4,6 Trihydroxy-s-triazine). Should I go buy “bromide”? Or do something with the stuff I already have? Please get back to me, my son wants to use pool and I don’t know if I should let him.

I'm getting confused; I don't know whether you are talking about the spa or the pool. Please go through the thread, and list the number of the posts (yours and other posters) that refer to your SPA. I'll split them off into another thread. (For example, this is post #45.)

Sorry about that. I'm talking about my pool. I'm losing CL during day only. I have the items listed above, tabs, stabilizer, and shock. I switched to BBB and I have this leftover. I suspect I have no stabilizer due to the daytime CL loss and the test strips stating it’s zero. I’m hesitant to use tab, stabilizer, and shock that I already have. I’m hesitant because I don’t trust the strips. I cannot get a good cya reading because I ran out of the Taylor Kit, r0013. I ordered more but it has not been delivered yet. The last Taylor cya reading was 70. This was 2-3 weeks ago. The strips are telling me there is no cya, which would make sense. I don’t know if my stabilizer can drop that much, so I am skeptical of the strips. If you tell me, cya can drop that fast, I need to add stabilizer. Should I use what I have on hand or go buy bromines?