| | Re: starting a 10g npt need a little help.
The reason soil works well is because it's made of decomposing organic matter. Also, the chemistry is rather different due to the organic content and constant decomposition.
Flourite has nutrients in it, but not nearly like soil does.
I've attempted NPT with only flourite substrate in a 29gal once. It wasn't bad, but I found myself using root tabs, which actually made for a pretty nice and fairly low maintenance setup either way.
Regardless, I much prefer soil over fluorite only. It's much cheaper, too.