ALGAE HELP-Chemicals are balanced-Not sure what else to do-ABOUT TO JUST GIVE UP.

Hi. I have algae in my pool and don't know why. I am at my wits end with this problem, and right now I so hate my pool. My chemical levels are listed below. I have a 25,000 gallon in-ground vinyl liner pool. New liner about 4 months old. 2 skimmers. Hayward sand filter. 2 jets. I use a FAS-DPD kit with a Taylor K-2005. I have always used chlorinating granules and 3" tablets in the past but just recently (about a month ago) stopped using both since I have high levels of CYA, I now use generic liquid bleach with 8.25% Sodium Hypochlorite. for pH I use Arm & Hammor Baking Soda. I have Not used any algaecide. I sweep mostly 2, sometimes 3 times per week. Very rarely vacuum. I have been getting small spots of algae growth mostly in the shallow end of the pool, not alot but a few very small spots here and there. Once I started having this problem, I got some advice earlier and was told to shock at really high levels which I did. I shocked to FC 17ppm to kill the algae. During this time I swept almost daily (I did miss a day or two). The pH and alkalinity were always good. After the high FC levels dropped I maintained FC to around 5-7ppm, however there were two times where it dropped to 3 or 4 within a day but I immediately added bleach to raise the level back up to around 7ppm. CC was always between 0-0.6. After about a 1.5 weeks or so I started seeing little spots of green algae again. I did the same routine a second time and got the same results in the end. Since then, I've just been sweeping algae as I see it but maintaining 6.6ppm FC, CC 0-.4, pH 7.8, Cyanuric acid 80, alkalinity 90, but again the algae always pops up in small spaces. I do not know what more to do. I even sweep around every crevice, corner, skimmers and jets with toothbrushes. Please any suggestions would be greatly appreciated. Thank you in advance. Anna (Current chem levels are listed below)
FC-6.6
CC-0.4
CYA-80
pH-7.8
alkalinity-90

You are getting algae because you are not keeping your chlorine high enough. Chlorine levels are dependent on CYA levels. With a CYA of 80, you should be keeping your chlorine between 5-10ppm ALL the time. Dip below 5ppm and you give algae a chance to start. Your shock level would be 20ppm.

So, test and add enough bleach to get back to shock level and try and keep it there until you meet 3 criteria:

1) You don't lose more than 1ppm from sundown one evening to within an hour of sunrise the next morning
2) You have no higher than 0.5ppm of CC
3) You water is clear and you have no algae spots.

Then, we typically advise keeping the chlorine high for one additional day and then let it drift down and keep it between 5-10ppm.

You will want to brush the pool while the chlorine is high and run your pump 24/7 while you are working to clear this up.

More about the CYA/Chlorine connection can be found here:> http://pool9.net/cl-cya/

Your K2005 kit cannot test chlorine levels past 5ppm. In fact, it will bleach out at high levels at make it appear that you have no chlorine. If you will pick up the K1515 add-on kit, it will give you the one test that the K2005 is missing that will allow you to test high chlorine levels. You can get it through this link:> http://pool9.net/tk/

By the way --- your pH readings will be invalid anytime your chlorine is over 10ppm with a Taylor kit (above 5ppm for other kits). So, if you need to test pH when the chlorine is high, mix one part pool water with one part distilled water and then test pH as normal with this mix.

Hope this helps.

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EDIT -- in a 25K gallon pool, each of the 121-oz jugs of 8.25% bleach will add about 3ppm of chlorine. Use that as a reference to help you figure out how much bleach you need to add whenever you test.

Watermom, thank you for the quick reply. I will shock to 20ppm, and follow the steps you provided. Also, the FAS-DPD set I have is the K-1515-A add on kit that I use in conjunction with he K-2005. I plan to do this on Saturday when I return from a quick day trip. Also, in regards to keeping the FC between 5-10ppm, would you recommend the higher say around 9-10. I live in North Carolina, the pool is in full open sun with no shade at all, and it's been so hot lately so the chlorine has been dropping 1-2 ppm each day, and even more when it rains, I would hate for it to fall below that 5ppm. I had mentioned earlier that it dropped to 3-4 once and that was actually after a big rainstorm. The FC was 8ppm and the next day it dropped to 4ppm. Is that normal?? Thanks again for all your help! Anna

Anna,
You'll need to check the Best Guess table that Lisa referred you to:

http://www.poolsolutions.com/gd/best...e-chart.html#a

With a CYA of between 60 and 90 (you have 80ppm), maintenance FC levels are 5-10 ppm, and shocking level is 20ppm. I personally prefer to be closer to the top of the range, since your CYA is closer to the top--say, FC at 7-10ppm.

But you'll see once your pool is clear where it "likes" to be maintain clear water.

Hi. I am at a loss, i am ready to just throw in the towel with my pool. I am having much difficulty maintaining the 20ppm for more than a day. Once I get to 20ppm at dusk I re-check in the morning before leaving work at 7am and it drops a little to 19ppm. I add a little more, and then re-check when I get home from work at 5pm and it drops down to 13ppm. I add more bleach to get back up to 20ppm. I have been doing this consistent and get same results. It's been really hot here in NC which is burning the chlorine quite quickly and I am spending so much money on chlorine at $3+ per gallon. Each 121oz. liquid bleach is only giving me about 1.3 ppm and that is the generic brand from target and walmart, 8.25%. Any other suggestions?? Thank you.

How does your water look? Any patches of algae anywhere?

Are you consistently able to go from sundown to within an hour of sunrise the next morning without losing more than 1ppm of chlorine?