I just returned from a one-week vacation and have some pea green colored algea on the steps and a few spots where the walls meet the bottom of the pool. Most of it brushes away, but not all of it. The water is still clear. I've never had any algea before, so I want to make sure I do the right things in the right order.

Here are the particulars:

22k gallon inground gunite pool (standard white plaster)
SWG
FC = 3.5
CC = .5
CYA = 60
pH = 7.2
Temp = 82

The punp/SWG was on a timer to run about 9 hrs/day while I was gone and was set to 100% generation. We also left the solar cover on to minimize things falling in the pool while we were gone. I've had the SWG running since I got home this afternoon on "boost", but I don't really have any other chemicals at home right now (shock, clor sticks, algecide, etc).

I suspect step 1 is to bring the chlorine level way up, but the SWG won't get it there by itself. What is the best remedy, and should I add algecide?

Thanks
Charlie