i bought this tank myself, used, and the person had made their own stand for it as well. but yes, the bottom plastic is designed to sit around the base stand, not on the base.
RE: lighting, i ended up going with the Fluval AURA LED, attached with a couple layers of 3M VHB Double Sided Foam Automobile Adhesive Tape, and it was strong enough to grow mid column (for that tank) and higher, but not carpet plants.
RE: lighting, i ended up going with the Fluval AURA LED, attached with a couple layers of 3M VHB Double Sided Foam Automobile Adhesive Tape, and it was strong enough to grow mid column (for that tank) and higher, but not carpet plants.