Here's a rough color chart for high ranges with OTO: http://pool9.net/oto-chart/

As far as I know, I'm the only one who has advocated using OTO this way; certainly I've never seen a pool kit with color block for the high range.

I'll help where I can, but you have to understand: no matter what your budget is, your pool will NOT forgive you. And it will cost far, far more to clean up, than to avoid problems.

I'm sure you really want to swim. But you might consider replacing the cover on your pool -- leaving 1/8 exposed, to 'breathe' the gases that form when chlorine breaks down goo. Covering the pool with hurt the algae and GREATLY reduce the chlorine need to eradicate it. That's the only way I know to deal with your situation AND cut expenditures significantly.

You would be able to swim in the late evening, without increasing costs much IF you avoid lotion on the swimmers (chlorine demand) and pee (BIG chlorine demand). You could continue aeration that way, too. Just keep it covered when the sun is shining.

Best wishes.