Hi Coffeebean

I would use a brush to knock off all of the algea and wait for it to settle before vaccuming ( a soft bristle push broom works too ) . I have good results keeping the ALK in the 100-120 range , so I would say put some baking soda in first to get the alk up. It will raise the ph slightly too , so you might not need as much borax.

I dont have a link for it , but Mwsmiths bleach calculator is awesome. you can use it to figure out quantities of everything..

Lastly , the cya can be adjusted after everything else is in order.. the bleach calculator will tell you how much to use.