rubber flakes

Hey all! I've read through the other posts on this forum on black specks in water but am running into a bit of a cluster with my issue. I had some really bad corrosion on my hot water tank nipples and had the whole tank replaced in October. Catch is the plumber tried pulling the nipples after...

I have no intention to re-open a well discussed issue of rubber specks/flakes in hot water; however, the solutions mentioned previously either did not work or were not applicable in my case. I had been battling those flakes for some 5 months before my heater (Rheem XG50S06PV36C0) finally leaked...