So I just read Ecology of the planted aquarium by Walstad and for a while i was planning on just doing a low tech set up with the dirted bottom layer then cap it with a layer of substrate. Now however I'm planning on making a diy paintball set up so ill have Co2 entering my tank at a pretty constant level. So would it be best to avoid the walstad method if im going to be adding pressurized co2? If so should i just use some fluval substrate for a nano shrimp tank/eco complete?
In my experience, co2 or not you get crazy root growth when potting soil is involved. Only con: The mess you get if you move stuff in your tank a lot. (I do that)
I set up my tank with garden soil topped with sand for over a year with great success, but got really tired of the water never looking as clear as I would like because of the soil particles always making it into the water column. After that long of maintenance within the tank, the sand cap eventually just mixed in with the soil. If a fish moved too quickly near the bottom, soil would shoot up and get blown everywhere from the filter output. The filter was always a mess too from the soil. I decided to start over and am now using ecocomplete with blasting sand. I'm not discouraging the use of soil, I'm simply sharing my own experience.