Best Dirt Substrate Cap for Glossostigma
My next project is going to be a high tech 27 gallon cube. I'm planning on a dirt substrate capped with something, either BDBS or extra fine Contrasoil. I've grown glosso for several years in Seachem Flourite (regular stuff, not the sand) with ok results, but I usually have trouble getting it to keep growing horizontal. It seems like when it puts off runners, if the roots do not find somewhere to easily bury in the substrate right a way, the next shoot grows up. I've coupled this with very aggressive trimming, CO2/light are high, and I usually end up with a thick carpet of vertical-growing glosso.
I'd need at least 20L of soil for the scape I want to do, so a capped, dirted set up made the most sense as I don't want to break the bank buying tons of aqua soil. I also already have the peat moss/top soil on hand, so all I need is the cap. BDBS would be way cheaper, but I'm willing to pay $40-50 for 10L or Contrasoil.
It looks like in most pictures I've found, the majority of people who have good horizontal growth with their glosso use an aqua soil of some sort. I was wondering if anyone on here has found this to be true or if anyone has had luck with a fine, inert substrate such as PFS or BDBS.