Oldmac,

I would never dream of doing it myself, but I have a growing friend that keeps asking me why not. He seems to think that if you only use it to flower you could use it over. I keep telling him that you still can not tell what nutes are left in the mix because each plant absorbs nutes at different rates and just flushing the mix will not remove the nutes and additives you do not need. I'm tempted to tell him to go ahead a do it. I just do not what him to screw up a grow by doing like you said "trying to save money on soil".