The tubes are an aero/NFT hybrid. Most of the pump flow is bypassed right now and just recirculating. It will be utilized with two more sets of planting sites, 24 horizontal above the first 28, and 30 vertical on the wall behind the tank. Total of 82 planting sites in a 3' x 5' footprint. This is not the finished lighting. This was put together for construction, though I still plan on using fluorescent lighting.