I have an old (looks like a Fleck timer valve) water softener system that doesn't seem to be working well - think I need new media and figure its best just to replace the whole thing with a metered system. The question I have is what the risk is in over sizing the system? I have found Fleck 5600 stx on demand systems that look good and the 48,000 grain is only $30 more than the 40,000 grain (calculators say the 40,000 should be adequate). Second question I have is the Vortech tank technology worth another $150?