Just want to chime in since we were in a similar state last year with cloudy water.
Personally (and I think tfp rules say the same) don't flock. You end up vacuuming to waste, losing a ton of water and now have to add fill water. It sounds like you have difficult fill water, so I would avoid using products that require you to vacuum to waste.
That said, I know others say that they have high ch and don't have cloudiness, but we did. When I got my TA down to 100 (vinyl pool) my ch was less and my water is crystal clear like never before.
Also, did you put in new zerobrite? We used that this year and it took almost two months to clear the water. What finally helped was pulling the top off the sand filter, draining the water out and sticking a hose in to flush the zeo. The water was so gray coming out.
We put our filter back together and added a little de to the filter. Then with a little pop, in a week the water was perfect.
So keep up the chlorine levels so you pass the oclt, lower your TA to the appropriate level for your kind of pool, and wash the zeosand. Keep your ph near 7.6 or lower with your ch level. That high ph with high ch is sure way to get scale and it happened fast (two days) for us.
Good luck and don't give up hope. The folks here are great!