Black Algae kicking my butt. Now I need help please...

[grguy]

This spring I had a invasion of black algae. I assume its black algae. I have been a member here for a while now and your information has been invaluable. A wonderful resource. Previously I've been able to research from prior posts.
I've tried a lot of the methods; SLAMming, brushing, chemicals from Leslie's, prayer, confession
I have included pictures from today. We just got back off vacation and i took the readings
PH 7.2
Chlorine 2
Alkalinity 100
CYA 40
I entertained the thought of draining and power washing the pool until I found out the cost of refilling the pool. Holeeee Cow$$$
Please excuse the mess in the pump area. Electrician is coming tomorrow to rewire. The old conduit rotted away and we pulled new underground PVC...
So now i implore your help. Were having family and friends over for Labor day.

I just updated my sig, so if it doesn't attach properly, here's the details:
42,000 gal gunite 20 yrs old *Hayward T15 chlorine cell *Polaris 380 robot *Hayward cartridge filter

Thank you in advance for your help
Grguy - Mark

 

[jblizzle]

Welcome to TFP!!!

First step: Do the spots actually feel slimy? Have you scraped some off and rubbed on a piece of paper and see green?

 

[grguy]

Thanks JB
The spots do feel slimy and greenish. They are tiny spots though, not really measurable.

 

[ajw22]

Mark,

What test kit do you have? What are your CC?

A FC level of 2 is low even for a clean pool. So while you say you have done a SLAM Process i have to ask if you have really followed the SLAM Process process step by step at the correct shock FC level with no shortcuts using a good test kit?

 

[jblizzle]

Is all that black what you are calling the algae? Or is it just the really dark spots where the rest is metal staining?

 

[grguy]

jb, Yes I'm calling the black areas the algae. I hadn't thought about metal staining but I guess its a possibility...
AJ - I did the slam for 7-8 days with liquid chlorine and cleaned filters 3 times during that period. I've been using the Taylor Test kits.
Thank you all!