I've seen it posted here a number of times that the best range for PH when fighting algae is 7.2 to 7.2

The above explanation about ion levels shows why. So I think I'b be shooting
to get the PH to 7.2

To really get the kill going well, tonight, as soon as the sun is off the pool, dose it up to your shock level. Run the pump to circulate and re-test in an hour or so. If you see a big drop, dose it again, and keep doing that till you can't stay awake. This will cut the yo-yo out.

If the majority of the CL is consumed in the first couple hours after adding, the the algae can go right on growing again throughout a lot of the night. So check it every hour or so tonight.

Keep track of what it does and let us know.