we work very hard to come up with a water only soil for our girls.
it takes a lot of time because of the different species needs.
dont mess with any of the "soiless" mixes because your tryin to go "organic" which requires real dirt.
they are all good recipes though, just make sure you choose one with plenty of compost an/or worm castings.
i use 100% used soil an mix in about 20 % castings an compost to give its life back ..... then i add a lil food to put that back in (less the second time around because there is still food in there that has not been broken down yet.)
then if the mix feels "tight" i will add more perlite an thats it...... i mix it all up in a tote , cover, water (with EM an molasses) an stir about twice a week to keep plenty of air in there for the microbes. ....... in about 2 weeks or a month its ready to use. VERY VERY healthy , living soil when im done.