A little algea, help me kill it fast and balance my water!

Jun 18, 2012
25
Suwanee, GA
After being pretty frustrated with my pool company, I decided to order a test kit and it came today. Here are the results:
FC=2
CC=0.5
TC=2.5
T/A=155
CH=170
CYA=40
Sodium Chloride: 3000

I know I need to change these numbers and have a pretty good idea of what needs to be done after reading the entire school article library. As to the condition of my pool currently: I've just noticed some algea, green with a yellowish tint at the bottom of my pool. Not sure how long it's been there because my pool has a very dark, almost black pebble tech surface. l also noticed a black spot in the deep end if the pool, about the size of a small plate, but not sure what it is-an irregularity in the pepple tech perhaps? Also have an elevated stone covered spa where some scaling appears to be forming near the waterfall that pours back into the pool. The water is clear and I've "boosted" my pool for the last three days while I waited for the test kit. Let me know if you need any more info and I'll be happy to provide it.

So my questions are:
1) Which steps do I take first? I'm guessing shock-but then what?
2) How much bleach do you think I need to purchase, want to avoid going back and forth to the store. I suspect it will be 6%. BTW, I saw some "outdoor" bleach at Home Depot, but it did not specify the percent. Does anyone know if this is an alternative and if so, how much would I need? It was about a dollar more than the 6% concentrate.

Here's a twist, having a pool party on Thursday for my daughters' birthday...can I get this done by then?
 
Re: A little algea, help me kill it fast and balance my wate

Yeah, with visible algae, you should shock the pool. read "How to Shock Your Pool" up in Pool School and follow those directions to a T and I think you pool just may clear up in those few days because your algae outbreak seems minor. Either it will or it won't and there is little anyone can do to hasten the process. I don't know how muchit will take but I would purchase fifteen large jugs to begin. you can always user it so it won't go bad.

You don't report your pH....what is it?
 
Re: A little algea, help me kill it fast and balance my wate

Post up a PH number to go with what you have. Looks like your CYA is about half what it needs to be for a SWCG. I'd sure shock it at your CYA level now and use bleach to keep the FC up until it passes the 3 criteria for shocking before adding CYA to get your SWG in line.
 
Re: A little algea, help me kill it fast and balance my wate

I think the outdoor and splashless have some sort of thickener in them, so best to stay away. Your pool sounds beautiful, never seen a black liner -- post some pix if you get a chance and Happy Swimming!
 
Re: A little algea, help me kill it fast and balance my wate

Thanks for the responses. So I should shock, but what FC level given my CYA level of 40? Should I use Dichlor or Trichlor to shock-i read it also increases CYA which I need to do anyway. This also seems to be the cheaper route given the amount of bleach that I will need, i.e. approx 16 gal.

As for the PH, the simple color comparison says its 7.8. I was wondering if I missed something expecting that there would be a more accurate way to test for it (I'm using the TF100 kit) but don't remember seeing a test for it, just T/A. Did I miss something?
 
Re: A little algea, help me kill it fast and balance my wate

Hi Manalex:

Click the Chlorine/CYA Chart in my sig for the appropriate shock FC target for your CYA.

My first choice of chlorine to use to shock is bleach / liquid chlorine. To raise CYA, I favor using a dedicated stabilizer product. This combination gives you better control than using trichlor/dichlor. With that said, you can certainly use trichlor/dichlor to shock since you need to raise your CYA level anyway, plus it will lower your pH (which is currently a little on the high side) . If you have some trichlor/dichlor laying around, this is a good opportunity to use that up. Per the Pool Calculator, if you used 18 16oz bags of dichlor (288 oz total) in a 35K gallon pool, you would increase the CYA from 40 to 71 which is a good CYA level for a SWG pool. If you use this approach, keep in mind that you will need to test not only the FC level during the shock process but the CYA level as well. As your CYA increases, you will need to adjust the shock FC target continuously since that will increase as CYA increases. If your CYA level increases from 40 to 70, the shock FC target will increase from 16 to 28 - that's a 75% increase!

If you go the trichlor or dichlor route to shock, I would have some bleach / liquid chlorine on hand since I would discontinue the dichlor or trichlor once the CYA level gets into the 70's. At that point I would use bleach / liquid chlorine for the remainder of the shock process.

As for the pH test using the TFT kit, here's a link to the instructions: http://tftestkits.net/Test-Kit-Instructions-10.html. pH test is in the "Daily (or as needed)" section.
 
Re: A little algea, help me kill it fast and balance my wate

Thanks Bo! I'm going to check the pricing again. Going the dichlor/triclor route may save a little money becuase I won't have to purchase the stabilizer-albeit a more complicated process. If the difference is not significant then I'll go the liquid bleach route. To be honest I'm tired of buying pool chemicals-been given bad advise and the dollars have simply gone down the drain...

Anyway, I did look at your chart but it only gives the shock value for a CYA of 60, nothing less. I'm at 40-how do you determine the appropriate FC number?

As for the test kit, yes, I followed the direction, I just thought that the kit would have a more acurate way of mearsuring PH. My old eyes can only tell the difference between extremes in the shading-I said it was 7.8, but it may have just as easily been 7.5 :(. Even an old fart like me can count drops. My son (with fresher eyes) thought the 7.8 value was more correct so I went with it.

As for a pic, here's a computer rendering when it was in the design stages-sorry, don't have an actual pic here at work. It's pretty much spot on though. However, water looks cleaner in the pic, but I'm confident we'll get it there soon :)

poolphoto.jpg
 
Re: A little algea, help me kill it fast and balance my wate

Manalex:

Nice setup!

Since you are at a CYA of 40, I would use the amount in the Non - SWG Pools chart (top chart on Chlorine/CYA Chart page) to determine your CYA target FC shock level. Start off with an FC level of 16 for a CYA of 40. Note that these FC shock targets are just that - targets and not minimums. There is some buffer on either side of these targets. The more diligent you are at maintaining the target FC level throughout the shock process, the sooner you will complete the process. Again, keep in mind that your target shock FC level will increase as your CYA increases (which will be sooner than you might think using trichlor and especially dichlor).

Here is an article showing how to properly do the shock process: http://www.troublefreepool.com/pool-school/shocking_your_pool
 
Re: A little algea, help me kill it fast and balance my wate

Went to WalMart last night and pickup up 4 cases of Pool Essentials Shock. Each case contained 5-1lb packets of treatment containing:

53.5% of Trichloroethane-s-triazinetrione*
46.5% of Other Ingrediants
*available Chlorine 48.6%.

Added 17 lbs (bags) of the treatment last night around 11pm, yes it was a long day.

This morning, I got the following test results:
FC=30.5
CC=0.5
TC=31
PH=7.4-7.3
T/A=150
CH=170
CYA=55
Salt=3200

Have a few questions:
1) Should I be concerned about the FC level getting as high as it did?
2) I assume the CYA levels will continue to increase-correct?
3) What, if anything, needs to be done now?
4) I expect to retest later this afternoon around 4pm. Am I ready for an overnight test-water is clear, no sign of algae? Pumps are running, cleaner and pool mode. All the treatment appears to have dissolved overnight.
5) What level of FC is it safe for the kids to go swimming?

Thanks in advance.
 

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Re: A little algea, help me kill it fast and balance my wate

1. I would be a little concerned with it getting that high. You're still below Mustard algae shock so it's not terrible.
2. If you keep adding Trichlor, the CYA will keep increasing. Your shock level will keep going up as well.
3. I'd say brushing.
4. Be sure the swcg is off and I'd run the test tonight and see what happens.
5. You can swim up to normal shock level.
 
Re: A little algea, help me kill it fast and balance my wate

Thanks Bama...Don't plan on adding any more Trichlor, planning on using bleach going forward. I too was a bit concerned on how hi the FC level got without getting a commensurate increase in CYA-although that will change I know. More brushing will occur this afternoon. The swcg is off.

Thanks Robbie for your response. Yes I read the Pool School articles-all of them, and many posts as well. I guess I should have been more clear in my question. I was really referring to the higher than expected levels of FC. I wasn't sure if it was too high given the level of CYA currently in the pool, and if it was, what needed to be done in order to correct the problem, if anything...

Thanks for the input thus far, its been great. I'll post up results as they develop so that others will be able to follow the progress as well in case they have similar problems.

A
 
Re: A little algea, help me kill it fast and balance my wate

Manalex said:
Added 17 lbs (bags) of the treatment last night around 11pm, yes it was a long day.

This morning, I got the following test results:
FC=30.5
CC=0.5
TC=31
PH=7.4-7.3
T/A=150
CH=170
CYA=55
Salt=3200

Have a few questions:
1) Should I be concerned about the FC level getting as high as it did?
Your main concern is why it's not higher. A dose of 17 LBs of Trichlor should have raised a 35,000 gal pool into the 50 ppm range
2) I assume the CYA levels will continue to increase-correct?
Yes. You've added about 30 ppm of CYA as a result of the Trichlor. It won't show up right away. Takes about a week to fully register on the test
3) What, if anything, needs to be done now?
Keep an eye on your PH. Your PH must have been very high to come in at 7.4 after that much Trichlor. PH reads falsely high when Chlorine levels are above 10 ppm.
4) I expect to retest later this afternoon around 4pm. Am I ready for an overnight test-water is clear, no sign of algae? Pumps are running, cleaner and pool mode. All the treatment appears to have dissolved overnight.
Sure, but your pool might not be ready to pass it. Only one way to find out. Test it tonight after the sun has been off the pool for a couple hours. You might luck out. That Trichlor bomb might have committed the genocide you were hoping for.
5) What level of FC is it safe for the kids to go swimming?
Until you pass the OCLT test, the FC doesn't matter. Flunking that test means you have organic matter in the pool. If the Chlorine is busy killing Algae, less is left to combat any pathogens. Any Algae left will quickly grow and deplete Chlorine levels to zero if not at shock levels. It's safe to swim up to shock levels. In your case with a CYA of 70, that's anything below 28 ppm. Let's get past the OCLT first. Make sure your SWG is off. If and when you pass, let your Chlorine drop to normal and test that PH asap.


Thanks in advance.
 
Re: A little algea, help me kill it fast and balance my wate

Scrubbed the pool, there was a lot more algea than I had orinally thought! At 6pm tonight I got the following results:

FC=22.5
CC=0.5
TC=23
PH=7.2
T/A=140
CH=175
CYA=55
Salt=3200

Pretty big drop in FC in less than 24 hrs and today was a nice day, not unusually hot, at least not by Atlnata standards. Chlorine must be working over time!

I'm surprised that CYA was unchanged at 55. With that level of CYA, the 22.5 FC value is still above the recommended FC, so it doesn't look like I need to do anything about it at this point.

PH, on the other hand has fallen, do I need to do anything about that while shocking?
 
Re: A little algea, help me kill it fast and balance my wate

I'm getting 70 for your CYA. 40 from the first test and 30 from the 17.LB of Trichlor. Takes awhile for the CYA to register on the test but you should assume it's there when looking for your shock number. Did your water turn milky when you added the Trichlor or when you brushed today? If not, test now for the OCLT test. Make sure the SWG is off and you test again before the sun hits the pool tomorrow morning. Forget the PH for now and concentrate on passing the OCLT.
 
Re: A little algea, help me kill it fast and balance my wate

Assume the CYA is 70 since it won't show up on the test yet. Keep FC at that shock level.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone :)
 
Re: A little algea, help me kill it fast and balance my wate

yeggim said:
I'm getting 70 for your CYA. 40 from the first test and 30 from the 17.LB of Trichlor. Takes awhile for the CYA to register on the test but you should assume it's there when looking for your shock number. Did your water turn milky when you added the Trichlor or when you brushed today? If not, test now for the OCLT test. Make sure the SWG is off and you test again before the sun hits the pool tomorrow morning. Forget the PH for now and concentrate on passing the OCLT.
I'll check levels again in the morning, but don't think the test will be valid. Kids were in the pool and the sun didn't go down until well after I took the last test (at 6pm). I didn't expect to do the OCLT test because I still saw some algea while I scrubbed the pool walls. SWG has been off for a couple of days. Never saw any milky water.

jblizzle said:
Assume the CYA is 70 since it won't show up on the test yet. Keep FC at that shock level.
So I should increase FC from 22.5 to 28? Per the calculator, would that be 4-96oz jugs of 6% bleach to do the job? Just want to make sure I'm doing this right.

Thanks
 

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