Problems with Algae

[mortimay]

I have been fighting algae in my pool for a while. We haven't been in it for a couple of weeks. I had the solar cover on it and it was in the high 90's and I let the chemicals slide. When I pulled the cover off (two weeks ago) I had algae. I vacuumed to waste, broght the chlorine up (the other numbers were ok at that time) and thought I got rid of it, but it just seems to keep coming back. I've had to add water (from the well) about four times. I added two gallons of 10% chlorine last night about 9pm. These are my numbers this morning:

Chl 12 (shot-glass method)
pH 8.4
Alk 180
Stabilizer 30-50 (per test strip)

I haven't been able to make it to the pool store to get results from them. Please help me keep this under control before I end up with a swamp again!

Thanks!

Forgot to add that I have an above ground, 27' x 4' pool, about 17,000 gallons.