Looking for some advice.....
I have a couple of PAL 2000 lights in my 19,800 gallon Fiberglass pool with a Salt Chlorine generator, one in the shallow end between 2 returns and one in the deep end just a little below the skimmer. The light has a clear lens cover that can be removed and rep;aced with colored ones if I want to change the color of the light. We never do this, but it is on the inside of the removable lens cover that I get some algae buildup.
This is our 4th year with the pool, and it has only happened the past 2 years. Also, it is only on the lens cover that is in the deep end just below the skimmer.
I tested water last night and here is what I have.....
Fc = 7
Cc = 0
pH = 7.6
TA = 70
CYA = 50
CH = 190
So my numbers look reasonable (need to bump CYA and CH just a bit), yet I still get a little algae in the light cover. My guess is that the circulation inside the cover is not too great and maybe I can drill some holes to improve that. But..... how come i do not have algae in both lights?
I am stumped.