I have been on planning on changing my mexican Pinguicula soil to a pure mineral base. I am currently using the sarracenia northwest mix which contains sand, peat and perlite. It just seems a little too wet. After reading as many posts I can on this forum on pure mineral mixes I am still confused which one to go with. I am growing my pings under 7 4 ft sunblaster t5's hight output. I have read that the addition of dolomite and iron oxide is a great benefit. Can some of you folks share your pure mineral soil recipes? Thanks!