Problems with Algae

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.

Tsk, Tsk. You can't let the water chemistry slide or this is what happens!

You'll have to keep your pool at about 15ppm consistently (test and add chlorine as many times per day as you can to get back to 15) until you can go from sundown one day til within 2 hours of sunup the next day without losing more than 1ppm of cl. Run your pump 24/7 and clean the filter as needed.

Your ph is also too high but if you tested it when your chlorine was high, then the reading may be inaccurate reading higher than it really is. Test it again before the next dose of chlorine. If it still shows 8.0 or above, lower it with some muriatic acid. Your TA is also high so you can work on both at the same time. See details about that in the following two linked threads:

Using Muriatic Acid Safely

Lowering Alkalinity Step-by-Step

You really need to get a good test kit. Test strips are pretty unreliable and inaccurate much of the time. See the Amazon link in my signature line below for the kit we recommend -- Taylor K-2006. Only order when the seller is listed as Amato Industries. Other sellers are sending the K-2005 kit instead which you don't want.