I forgot to mention, the holes in the tubing is ok, but think about it. once the gas falls on the plants It keeps going down. What's more important is to have circulation in the room. CO2 is heavier than air, but with a fan it will spread the gas and continue to circulate it around/through the leaves which is more beneficial then having it cascade down onto the plants then hover on the floor. It's not the base of the plant and dirt that benefits from it, it's the leaves. I use just a tube that's inserted into the back of my fan. My babies are doing great.