Are the sides of your pool covered with this stuff you think is algae, or is it just the bottom? And how much chlorine are you losing overnight in ppm? My vote still is dirt, but I could be wrong. I can tell you that just because your Aquabot has been used that much, you can still have dirt settling in your pool, but if you really think it's algae, then the only way to get rid of it is to shock it and keep it shocked until it goes away. I just hate to see you waste that much chlorine if it's not really algae. Also, if you're going to shock it and maintain that shock, you need to do it with chlorine (bleach)--the SWG can't keep up with a maintained shock level and you're putting a real draw on the cell life. The SWG will be much better at maintaining a baseline chlorine level than it will maintaining shock level (which is 15 ppm, now that your CYA is 20,not 10--if you're only going to 10 ppm, you're not going to win the battle if it is algae).

As far as your stabilizer goes, I don't know by which method you added it, but it can take several days for it to completely dissolve into your water, so I wouldn't add any more until you've waited a couple of days and re-tested for it. Having the lower CYA reading is better than having none at all--you do have to maintain a slightly higher shock level, but at least you're not losing it all to the sun. Most people with SWG keep it around 80 because it's supposed to optimize cell life, but while you're shocking with other forms of chlorine to clear the pool, I would keep it on the lower side for now.

Janet