I'm torn on this, here's the situation... (skip to the bottom for the short version)
I've got a 90g and I'm trying to get more heavily into plants. I have a 8" Jack Dempsey that digs and a peacock eel that burrows...everything else in the tank is pretty plant/substrate neutral (so long as I stick with sand/something that my bichirs won't confuse for food).
Now, the JD digs, but he's predictable about it. I always have some sort of cave-like territory for him to claim, and he ALWAYS digs that cave out until he can see the bottom glass in the center of it. And thats all he digs at. Basically, this means that its not too hard for me to keep my plants planted (for the most part...my wisteria gets pulled up pretty often
) AND--more importantly--it means that I really want to avoid using a layer & cap method for substrate, as I think it would all get dug up and turn into a mess.
So, I want something either very dark brown or black. Right now I have a mix of colorquartz black & chocolate colors. The chocolate was supposed to be a dark brown, but its a pretty bright red under tank lights. I really don't like the color and its my main motivation for changing the substrate. I could simply siphon out half (or more) of the sand, get another 50lb bag of colorquartz black and darken up the mix, but I'm not sure thats the route I want to take.
I THINK I want something like eco-complete to help with my plants, but I'm not sure its necessary. I won't be putting c02 on this tank for a long time. On the same note, I know someone locally who doesn't use c02, but does have eco-complete. I get my wisteria from her and it doesn't grow nearly as well in my tank as it does in hers. I know, could be a lot of different factors, but I feel like the substrate has a lot to do with it. Other reason for wanting eco-complete is to get a bit more of a natural look than I get with the colorquartz.
So I guess here are my main questions...
Is eco-complete OK with a fish who digs?
Would colorquartz + roottabs (I'm currently using osmocote pot-shots) do just as well as eco-complete as far as nutrients assuming no dry ferts and no c02?
Is there a better option that I'm missing? Keep in mind...I'm not going to make a layered substrate, so I don't think MTS is an option.