I think I have an algae bloom - I'm finally SLAMing

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Otis Campbell

Otis Campbell

0
LifeTime Supporter
Mar 5, 2013
122
Lewisville, TX
I'm out of town and my wife reports the bottom of the pool "looks murky" and there are green deposits forming on the side of the pool. Our pool build was completed last September so we are entering our first summer with the pool. What should we do? I can test the water tomorrow night when I get home but I'm afraid this could get out of control by then.

Thanks.
 
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Re: I think I have an algae bloom



If you have a stockpile of chlorine at home, ask the wife to pour three jugs in. That should at least stall it a little.

I know what you'll be doing this weekend.;)

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Re: I think I have an algae bloom

Does she have a test kit with her? Tell her to check it. It's not that hard! If she can follow a recipe and cook, she can test the water! Add the liquid chlorine to SLAM the pool and brush it. :goodjob:
 
Re: I think I have an algae bloom

She took a sample to Leslies and bought a bunch of stuff. I know we spent too much money so you don't need to remind me :( It solved the problem before I got home which was her goal. We are new at this and I haven't been able to devote the time to get comfortable doing my own testing and managing the chemicals myself (and save money).

Anyway, she went back yesterday and got another test done. Here are the results:
FAC 0
Salt 3200
CH 240
CYA 60
TA 100
pH 7.6
Phospates 100 (it rained the day before and that morning so the guy at Leslies theorized that was the cause)

So I need to add cholrine so I don't get another algae outbreak don't I? Is it as simple as adding bleach? The PoolMath calculator says I need to 127 oz of 8.25% bleach.

Thanks for your help.
 
Re: I think I have an algae bloom

I get a lot more than that. For 28000 gallons and a CYA of 60 with a SWG, target FC is 5ish and that calls for 211 ounces of 8.25% bleach. :shock:

FC is dependent on CYA level. Forget that "3 is ideal" mumbo-jumbo. That's what got you algae in the first place!
 
Re: I think I have an algae bloom

Otis Campbell said:
We are new at this and I haven't been able to devote the time to get comfortable doing my own testing and managing the chemicals myself (and save money).
Click to expand...

I know "they" don't like to hear this but using the pool store for tests can get you by, as long as you don't BUY !! The key for me is "yup, I still have some of that at home" and "I think I have enough, I'll check".
I've stocked up on a few cases of liquid chlorine, a 12lb bag of baking soda, gallon of muriatic acid and a big jug of stabilizer( it keeps and it's a lot cheaper per oz then the smaller size). The stabilizer I still get from the pool store so they're getting something. Finally have a TF-100 on the way :)
 
Re: I think I have an algae bloom

I disagree. The pool store testing will not get you by ... it has been proven time and time again on the forum that the results are inaccurate and not repeatable. And it certainly will not help for the SLAM process.
 

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Re: I think I have an algae bloom

I appreciate all of the advice. I need more. I'll give you an update including disclaimers of ways I have deviated from TFP best practices.

I added chlorine Tuesday night. I didn't have any liquid bleach on hand so I used two pounds of a Leslies product. That's what I had on hand and work and family responsibilities did not allow me the time to buy liquid bleach.
I tested last night with my Taylor TF-100 kit to perform a FAS/DPD test. I bought this kit last September. I've never used it before. I did not read the advice on TFP about how to care for the kit so it spent the winter and spring in a cabinet on my back (covered) porch. I did the test and the water barely turned pink but it did turn pink. One drop of the next reagent and it turned clear which, if I'm doing this right, indicates 0.5 FC level. Since I'm new at this and I didn't store my test kit properly I took the Pentair test kit my PB gave me and did a test. Got the same result.

Questions:
1. Do you think my test kit is giving me accurate results? They seem to make sense since I started at zero and many of you believe I still have algae in my pool
2. I won't have the opportunity to SLAM until Sunday at the earliest but I don't want this to be out of control again where my pool is green. I added two more pounds of the Leslies stuff last night and will test again when I get home tonght. I do have the chance to get some liquid chlorine at Walmart on my way home. Should I do that and dump some in tonight?
3. If I start the SLAM on Sunday can my kids swim?

Thanks again and please be gentle.
 
Re: I think I have an algae bloom

Otis Campbell said:
Questions:
1. Do you think my test kit is giving me accurate results? They seem to make sense since I started at zero and many of you believe I still have algae in my pool
2. I won't have the opportunity to SLAM until Sunday at the earliest but I don't want this to be out of control again where my pool is green. I added two more pounds of the Leslies stuff last night and will test again when I get home tonght. I do have the chance to get some liquid chlorine at Walmart on my way home. Should I do that and dump some in tonight?
3. If I start the SLAM on Sunday can my kids swim?

Thanks again and please be gentle.
Click to expand...
1) The easiest way to tell if the test works is to grab a bucket of pool water, mix in a cap-full of the bleach you snitched from the laundry or a pinch of the shock powder and stir it in, then try again. You don't even need to be accurate unless you want to know precisely. Just see if it goes way up, like above ten. Then dump that bucket back in the pool.
2) What powder are you adding? Read the label! If you're adding dichlor or trichlor, you're also adding CYA, which will just raise the SLAM level and make it harder to achieve. Cal-hypo may increase the risk of scale formation or cloud the water temporarily, but won't affect the impending SLAM process
3) It's safe to swim up to shock level. I would discourage it, though. You might create a lot of combined chloramines which irritate the eyes and skin.

If you can get some liquid bleach tonight, why not start the SLAM tonight after the kids are done with the pool? It actually works better after dark, since the sun isn't robbing free chlorine. Test everything, adjust pH if needed, and use the CYA reading to determine the shock level. If the water is already clear and you get a good kill going, it could all be finished before the weekend.
 
Re: I think I have an algae bloom

Richard, Good suggestion on the bleach test. Hopefully my test kit is working properly or I won't be able to start the SLAM process until I get replacement reagents. Thanks.

The Leslies product is dichlor, rats. So I'll check my CYA before I get started. Using the Chlorine/CYA chart and the PoolMath tool it looks like I'll need somewhere between 8-10 gallons of 8.25% bleach depending on how much I've raised the CYA. Since I have a baseline from the pool store test won't my CYA test also be a good check on my test kit? I'm thinking if I get a reading of 60 or higher that would be a reasonable result based on the dichlor I've added.

So a question about the SLAM process. Let's say for discussion purposes my target FC is 24. So I add 8 gallons of bleach and wait an hour then I test again. If I'm and I'm at 24 how long do I need to maintain 24? If I'm less than 24 then I add more, using the PoolMath tool, and test an hour later, correct?

More questions are sure to follow. Thanks for the advice.
 
Re: I think I have an algae bloom

Cut and paste from: http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

You would need to maintain the SLAM level (24) until you are done. You are done when:
CC is 0.5 or lower;
You pass an OCLT (ie overnight FC loss test shows a loss of 1.0 ppm or less);
And the water is clear.

When all three are true, you are done SLAMing and can allow the FC to drift down to normal levels.
 
Re: I think I have an algae bloom

I'd get 8 to 12. If you don't need that much you'll just use it for maintenance. I went through a number of 4gal cases doing my SLAM.
Depending on how long the SLAM takes the CC is what should go down at the end of the process.
Yes CC is ... but I'm not sure what part of the test gives it to you. That part I'm not sure of. I don't get my kit till tomorrow according to UPS :-(
 
Re: I think I have an algae bloom

I bought some 10% chlorine at Lowes on the way home. I tested my water to get a baseline before trying Richard's suggestion of adding chlorine to a bucket. Here are the results that I got.
FC = 3
CC = 4.2
CYA = 40

Given the 4 pounds of dichlor that I've added over the past 2 days does the CYA make sense? I'm going to go ahead and add the chlorine for slamming but would appreciate any insight or advice. On second thought, with CYA that low I'm not sure that is such a good ides.
 
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