Well, after lurking around here trying to soak up as much information as I can since 2012, I finally decided to register.
My pool was built more than 20 years ago (best guess, based on who owned the house when the pool was built), and, according to the folks I bought my house from, was trouble-free for them.
Since moving in, I have dealt with all the common types of algae with either BioGuard BackUp or AlgaeKill II (prefer the AKII, but would rather not have to use it at all...). Last summer, I finally got into the habit of taking a water sample in to the local pool store every Saturday morning to let their computer tell me what chemical adjustments to make. That still didn't keep me from dealing with algae from time to time...
After having the pool opened this year (Thursday, April 30), I noticed the water was very cloudy (couldn't see my main drain in the deep end) and was a beautiful shade of teal green. Ugh.
I added the little bit of AKII I had remaining from last year (about 6 oz., IIRC). It had apparently gelled during the winter, so I got some liquid out while about 1 oz. remained in the bottle. I then saw the quart of BackUp the pool company had left for me and decided to add that, since I didn't know whether the AKII was still any good. I know, this was not the best idea. But it gets worse.
When I went into the pool store to pick up more Basic Tabs, AKII and SmartShock, they advised me they had already added a quart of BackUp at the time they opened the pool. So, I got home to very foamy water.
What I've Done So Far:
I have continued to add Basic Tabs to my skimmers (no auto chlorinator is installed), but have not taken a sample in to be tested. The advice was, "We're going to be getting a ton of rain in the next week, there's no sense in getting everything balanced now, only to have to start all over after the rain."
We got anywhere from 2-4" of rain yesterday, so I put 3 pounds of SmartShock in before I left for work this morning. It foamed up immediately upon mixing with the pool water.
I've already ordered a TF-100 Test Kit and am going to take matters into my own hands this year (no doubt with lots of help from y'all...), hopefully with better results.
I'm at a bit of a loss as to what to do next. I know I'm flying blind by not having test results. I also know I have WAY too much algaecide in my pool. And I now have green blotches appearing in the bottom of the shallow end, though I have no idea if that is algae or copper from the algaecide...