When I did my flush, after the initial flush with a hose while the truck was running for 30 minutes, I filled it with distilled water every morning, drove it to work and back and opened the radiator drain with the nose pointed downhill at night. I did that for a week before converting
If I were you I would keep flushing until it is almost clear. You are only about half way there at 16 gallons. The system holds 7 I believe.
2006 F250 Lariat Supercrew, ESOF 4x4, 18" tires, FX 4, HD Alt., block heater, Integrated Trailer Brake Controller, Upfitters, power rear window, cab lights - delivered 10/25/05
Ford Remote Start; High idle mod; Timbren load levelers, Scangauge II, Blue Spring upgrade, Quick Start 200 amp large frame alternator, 2 batteries January 2010; GPCM replace October 2011; 2 EGR valves; EGR Cooler replaced 12/30/11; Performance Machine & Mfg. coolant filter added 1/2/12; Rotella T6 5W40 oil; turned rotors, replaced brake pads for 1st time 1/7/12 101K miles; GPCM, both subharnesses and all 8 glowplugs replaced 1/5/13 at 118,000 miles; 2 Ford batteries replaced under battery warranty twice, the latest 9/18/2015; FICM power supply board replaced with Dorman board 11/20/13. Coolant flushed and replaced with Prestone ELC 9/27/14. STC fitting 10/19/14; Dummy Plugs 11/8/14; Turbo rebuilt 11/29/14; cold side CAC tube and boots replaced with metal tube 1/24/15; replaced hot side boots 1/30/16.