Debating ... Instead of using the puffed clay balls [Leca/hydroton], if I could get away w/ lava rock as the bottom layer of my terrs. My old 30 gal terr has the hydroton as it was on hand at the time. But for the two big terrs [a 55 gal & a 90 gal] I would need to buy more "rock" no matter which substance I decide to go with. The lava rock would be a lot cheaper which is its primary attraction.

Also, my 90 gal tank came with the white plastic drain board/bottom.

Since I'm not doing fish -- strictly plants, should I remove it or just put my media directly on top of it? Would it matter?