Considering Semi-Overhaul, need some info

So I've had a planted tank for about a year now and it's gone through several stages and several overhauls. I'm actually at a point right now where I'm starting to like the way the tank looks, but I'm considering making a few (majorish) changes.

The tank is 15 gallons. I have 2x 13W CFL spiral bulbs as the light source (photoperiod right now is 8 hours). I have a pressurized CO2 system as well, but I'm not dosing ferts. After getting tired of algae issues with a higher light set up I decided to decrease the lighting and go with a moss / low light (i.e. anubias petite and some dwarf clover) setup.

Both the moss and the anubias and doing wonderfully; the clover is starting to grow, but it is amazingly slow.

Which brings me to what I'm considering doing. My substrate is currently Schultz Aquatic Soil (about 1.5") underneath a layer of just regular natural colored gravel I got from Walmart. Unfortunately when I started this little endeavor a year ago I didn't do much research, and I've been wanting to switch to a dark substrate for about 6 months now but just haven't brought myself to doing it.

So that's the first thing: replace the substrate. I was thinking about doing something with the Earthworm Castings and Black flourite sand (still not certain on the particulars there).

Now, I would like to try a different ground cover. I think the clover is going to end up being too tall for my purposes (even the submerged growth gets to be about 1" tall, which is almost as big as my anubias petite). Also, I can only imagine how long it's going to take the stuff to actually fill in at the rate it's going at.

So I was considering glosso. The thing is, I don't want to up my lighting past 2WPG. I'm still having some issues with BBA at my current light level (which I think I've solved, I was getting it on some of the driftwood that was pretty much directly under the lamps, about 1" away from the bulb. Hopefully the issue is now solved), and I really don't want to get into the mess I had 6-8 months ago. I know I've read that glosso can be grown at lower light levels if it's given the right conditions.

So yeah...thoughts? Is this do-able? Any suggestions on how to make the process easier for myself?

thanks

 

i'm assuming i'm going to need to add ferts once I plant the glosso. i'm not right now because, from my understanding, moss / anubias don't need much in terms of ferts and I didn't want to overload the system with excessive ferts (creating the circumstances algae loves). since glosso actually grows at a decent rate i'm assuming it's going to need a constant supply of nutrients

from the bit of reading i've done (including some posts by Tom), I was under the impression that castings would last longer than that.

 

Are there any more cost efficient ones than ADA and the like?