sludge/goo behind inground pool light

[Schooled by Pool]

Thank you kelemvor. I finished with the water refill, adding what bleach I had left to be proactive when I was filling it.

New readings (in daytime sun, mind you) are

fc 13.5
cc 0
ph 8+
acid demand 2
ta 100
ch 220
cya 60 (yes, 60!!!)

So, do I go shock to the mustard algae level of 34 or shock to normal level of 18? What do you suggest? Thank you for your help. I am grateful.

[Schooled by Pool]

Update: I went with the Mustard Algae Level. The pool was cold and I figured I had about 2 weeks before it would be warm enough to swim in. Since then, I have remained algae free.

On another note, I have been doing what I learned on this site, testing daily with the Taylor Kit, giving the pool what it needs every day, taking care of weekly maintenance, using BBB method. The pool has been crystal clear for a month. The next door neighbors can't believe how clear it looks. Their daughter saw it and said "Its clear and blue! I don't believe it. I have never seen it like that!" It seems the previous owner never got past a green tint, even if he did clear it once in a while. So, I am saying thank you to Pool Forum. I never would have gotten to this point without the help I have received here, both in my understanding and in results. My kids have used the pool every day for the last 2+ weeks. They love it...and the pool has been algae free and balanced for a month, which makes me a happy camper.

FC between 5-9 every day
CC between 0-1 every day
PH 7.7 every day
TA 90
CH 240
CYA 60

Thank you!!!!!

[Watermom]

It is good to hear another satisfied member telling of how much he has learned about maintaining a pool. Thanks for your post and hope you have a great swim season.

By the way, as far as I am concerned, there are two seasons -- "swim" season and "can't wait til it's swim season again" season.