I'm getting together all of the stuff for my grow room and $ issues are forcing me to make compromises. I'm using an ebb and flow system and like the idea of clay pellets, but they are very expensive compared to gravel from home depot. Will well washed pea gravel work just as well? I read on these forums mention of red lava rocks and checked them out, and they look good, very light and porous. Does anyone have any experience with these? and should I mix with another medium? I was planning on rooting clones in rockwool then transplanting to pellets or gravel.