I grow tomatoes in kitty litter buckets filled with 3/4" stone, run a pipe out of my continuous flood/continuous flow GB and into the top of the buckets. Have a pipe on the inside of the bucket going to the bottom to insure complete water turn over, and exit the bucket about 4" below the top of the stone, back to the fish tank. Also running the buckets CF/CF. Had the same 2 tomato plants growing since May this way, no need for an airstone.