Have you checked into "blending" or High Gravity Brewing? If your mash tun can handle a bigger load of grain then you can brew a higher OG beer with proportionately higher hops and other additions, and then can add it to pre-boiled water in your fermenter to achieve the OG you want. Or, do what some of the big guys do by blending pre-container so you get the most from your fermenter, of course they use perfectly controlled water for this and I don't want to go there until I am very sure about the process. I am thinking about blending using my new system to get me to a whole 15.5 gallon final batch. The pressure fermentation technique I use allow me more in the fermenter because of subdued krausen height, and I know how much is always left in my fermenter afterwords. So, if nothing leaves the fermenter until it is finished and you take good gravity readings, I should know how much beer is going into my serving/"secondary" ahead of time. Knowing this, I could boil my water after pitching my yeast or even wait a day and then boil and add my cool measured (because hot water expands and will give you a wrong reading) pre-boiled water to the soon-to-be serving keg. Once in there, I will purge it with the CO2 from fermentation (spunding valve on serving keg not fermenter) and will remove even more of the remaining O2 in the water. Then at transfer time, I will bleed the spunding valve on the serving keg as I'm adding back gas to the fermenter, just like serving a beer. The higher gravity beer will mix with the same carbonation level water and then mature just like normal. Where it at, where it at, where it at??? I love the flexibility this gives me in the very near future even more so than it does right now, and I love it now .