Well, that's pretty good info for a newbie!
Every foot of water in your pool is 5287 gallons, which makes sense if your water is 4' deep. You can start adding bleach right away. I'd add 2 quarts for that first foot--one gallon for every 10,000 gallons. Walk around the pool pouring it in slowly, and a little more heavily in front of the hoses.
Return the "Algae Kill" if you can. You were VERY wise to read the ingredients and check us at PF to see that we say that's a No-No!
The other stuff, "Algaecide 60" is exactly the Polyquat we recommend! Home Run, Rookie! I never worry about the name, I just look for the "Poly....<something unpronounceable> ...60%" as the only active ingredient.
I wouldn't add more than a couple of ounces--a full quart will cause your chlorine level to drop to zero...that's OK but you have to know it's going to happen and boost the chlorine after. But an ounce to 2 ounces should be fine--just don't backwash immediately or the PolyQuat will wash out!
If you keep the chlorine in, the rainwater shouldn't be a problem. Be sure to test your pH though, everyday.
You are doing everything right so far! I can't tell you how much pleasure it gives us to see that!
Welcome to the Forum and to the wonderful world of B-B-B easy, simple and cheap pool care--that's EFFECTIVE!
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