I have a 64,000 grain softener mounted on the supply side (before the holding tank) on my rig. The water supply line generates the only inlet pressure I use. The down side of this configuration is that I’m restricted to using a ¾ inch supply line, but I’ve been able to work around that issue by using reducers. The softener tank also has bypass valves on it, so I can control whether or not I use soft water, how soft I want the water to be, or which of two machines it runs through.
There are a lot of things to consider if you go down this road. Based on my own experience, I would suggest that you speak to some water, boiler, and chemical experts in your area. There are also a couple of guys who visit these boards who a very knowledgeable about this subject. Try doing some searches.
Sounds like the Scaltrol product that Oguard mentioned would be worth checking out. It would probably be alot cheaper too.
Good Luck!
