changing coolant on 2007 2500HD

. . .Silica fallout is usually found in OLD antifreeze( REALLY OLD!!! ) & usually in Diesel engines IF not keeping up with their nitrate levels/ coolant filters. . . NOT an issue with todays coolants as they are formulated (When is last time in last 10 years anyone saw silicate fallout?). . .I worked a successful automotive cooling system shop (33 years) & yes, actually purchased FULL trailer loads (20 pallets) of coolant at a time. . .Only took a few classes on coolants & such but had 43 years in cooling systems industry addressing & solving problems with cooling systems. . .Also talked to several AC Delco guys(at trade shows) about their Dex-Cool problems & every one of them had a different answer. . .By the way your link did not work.. . .YMMV. . .