If lowering PH reduces the flakes, then it is probably the calcium being dissolved back into solution. So the the only long term solution is to reduce the calcium level in the pool.

Have you tested your fill water? If it has less calcium than the pool water, you can do a partial refill to lower it. Bleachcalc has a new refill function to help but you will probably need at least 50% new water.

In lew of a refill, keep your PH and alkalinity down toward the low end of the recommended ranges. This should help keep the calcium in solution.