Joe,
Ben probably did miss that part. He's out of pocket for a bit, so it may be a couple of days before he is able to get back to this thread.

A couple of questions for you? What kind of kit are you using? You cannot use the dilution method for extended periods of time, especially when you are going to really high levels like you seem to be doing.

I'm concerned what you may be doing to your liner with these kinds of high chlorine levels. Are we sure it is black algae?

Check that and maintain your chlorine levels for now until Ben is able to get back to you on this thread.

The way Ben suggests to check to see if it really is black algae is to scrape some off, and under your fingernail. Then, dry off, and smear the stuff under your fingernail onto a white index card. If the smear is green -- you have 'black' algae. Maybe you can try that to verify if it is indeed black algae.

I think we may have suggested it before up in this thread (don't have time right now to reread the entire thread) but in case we didn't, you need to get a good kit! (Amazon link below.)