What am I doing wrong?

[da_guy2]

So in the past, I've had 2-3 algae blooms a year so this year I was fed up and thought I'd keep on top of things to try and prevent them... well that lasted less than a month. Well, my pool is now green. Tomorrow I'm headed to the store to buy a half dozen jugs of chlorine, but for now I want to know what I'm doing wrong? My numbers are

FC = 3.8
CC = 0.4
pH = 7.6
TA = 80
CH = 100
CYA = 80

Is there something I'm missing? I had noticed some algae on the top of the solar blanket. Could that get into the pool and cause the bloom? If so is there any way to prevent that beyond not using a cover?

 

[jblizzle]

What has your FC level been historically maintained at? It is currently below the minimum for your CYA level ... that is likely your problem.

 

[da_guy2]

Hmm ya, I see that. I was out of R-0013 so I had estimated I was at ~50ppm of CYA based on the pool store test and how much I had added. As such I was running around 3-4ppm of FC. Once my shipment of R-0013 finally arrived I tested and it was higher than I expected. I guess I should have turned up the generator a bit to compensate, but I missed that part.