Hi,
you wont regret the Test Kit. It along with pool math will be your best friends.
If I were you, before I started teh SLAM, I would let the FC drift down to below 10.
Then backwash the filter and record teh pressure reading. This will be your "Clean" pressure.
Next, if your pH is high, then adjust it down to 7.2.
Then start the SLAM.
Here are the SLAM instructions. Make yourself intimate with them. Getting rid of algae by any method is a process. There isnt a magic cure. It will take days or more to get rid of it and get your pool crystal clear.
Pool School - SLAM - Shock Level And Maintain
The important part, is teh MAINTAIN the shock level FC. That level will be relative to your CYA.
The more vigilant you are about mainting the FC at shock level, the quicker it will go.
It would be easier on you if your CYA were lower which would reqire drain and refill half the water, but you can do it at 65. It will take twice the amount of chlorine.
Here is the FC/CYA chart.
Pool School - Chlorine / CYA Chart
Use only liquid bleach as your source of chlorine. No powder shocks because they add other stuff the pool which you do not need. Especially with your CYA at 65
Use pool math to determine how much liquid chlorine (a.k.a. bleach), to add in order to maintain the required SLAM (shock) FC.
http://www.troublefreepool.com/calc.html
You will need to brush all of the pool surfaces daily. Algae will will stick to the walls and grow biofilm over it to try and protect itself. Brushing will destroy it and let the chlorine kill the algae quicker.
Also, not a bad idea to take out your pool light. Algae likes to grow in the light niche and will drive you crazy. Its worth the effort.
You will need to run your pump and filter 24/7. When your filter pressure rises 20-25 percent above "clean" pressure, then it's time to backwash it.
