Brewed this yesterday with 100% RO water and built it to the Black/dark balanced profile on Bru'n water. I managed to get 5.5 gallons at 1.102. Got the wort down to 80 degrees and hit it with pure O2 for 60 seconds and then let it cool for a couple hours outside until it was at 70 degrees. I then hit it with 30 seconds more O2 and pitched a 3.5 liter starter (~650 billion cells) of Wyeast 1056. I proceeded to attempt a partigyle and pulled enough with my second runnings to get 3.25 gallons at 1.061 into the fermenter for a porter, I figure I have $5 into this one so if it sucks oh well. I am about to hit the original wort with another round of O2. Fermentation was already going nuts after 8 hours so I am hoping all the oxygen and the big starter helps it ferment out. I mashed about 1/3 of my dark grains for 30 minutes and then added the rest and mashed until I was getting constant refract readings (checked every 5 minutes). Big thanks to @PianoMan for answering questions I had on this one and giving me some guidance as this is the biggest beer I have attempted.