Algae just won't go away for good!

[floridadreaming]

Hello, I have been having trouble since June with algae. I am currently starting my 4th slam. Slamming with 8.5% bleach. What is happening is when FC is brought up to slam levels algae goes away. I was bringing to very high levels in June because my CYA was very high (over 100). Hold shock levels for several days as per process until all 3 conditions are met (clear water, holds level over night, CC .5 or less) It would take about 5 days or so for levels to drift down to normal, then algae would return. Noticed that on top step I was getting what started as a algae that had the appearance of Guldens mustard (yellowish-brown) thin line about a foot long, that would reappear first at the exact same spot. Brush it away and in an hour or so it was back in the same spot. After reappearing, then the algae would start to bloom on pool bottom and sides as a green algae. After the second or third slam it turned to a more burnt orange color. I assumed that this is mustard algae, and shocked to the appropriate levels, but it just won't go away for good. Any suggestions?

FC 44
TA 100
PH 7.5 before slam process was started
CH 80
CYA 65

 

[Mike59]

After you complete the SLAM, are you keeping your FC above the minimum FC for your CYA? In June you had a CYA over 100, but now showing 65. Did you drain water? If you did not, it wouldn't drop that much in a month...so perhaps your minimum FC is incorrect. I let my minimum FC go a little low 2 days and I got an Algae bloom. I've learned you MUST keep it above that number.

 

[mrcarcrazy]

Are you brushing steps and ladders, and light niche's? (along with rest of pool).

 

[floridadreaming]

I did a series of water changes to bring down CYA level over several days. I wasn't quite done with process when a full bloom erupted. FC was kept on high end through June and July. At end of July I had a family emergency and had to leave town for almost a week. FC level did get low then and now I have a mess I am dealing with. I know I can clean up the bloom, but again I have this reoccurring problem I need to figure out. Brushing so much it has become a full time job. No light in pool, removed step ladder. Also I am using TF100 kit to test. I am very frustrated!

 

[Mike59]

Letting the FC get low when you were away is what did it. Hopefully the SLAM won't take as long this time. But stay hopeful...your pool will return to crystal clear. What I do now, since I'm paranoid about getting another algae bloom, is I will do the OCLT maybe twice a week. As long as I'm passing that, I know I won't get any algae. It may be something you want to do once the SLAM is completed.