So plants needing about 3" deep of substrate... Plant substrate is very expensive... Those are all facts. Ive read i can mix sand with the plant gravel to give me extra depth. I am hoping to get some cheaper substrate and mixing it with about 33% bds.... Ive read you can do 50/50 mixture without much difference. I will be root tabing. Any ideas if that set up would work with swords and or dwarf tears?