I used the chopped 2 liter (which makes it even a little smaller) because as I was developing my sog style, I realized that the circumference of the container was my 1st limiting factor...plus I had read that plants tend to reflect what's going on below ground, above the ground...so if ya want yer plant to grow up more than it grows out...you use a container that's narrow but tall...aand I did that so I could cram as many as I possibly could into my space. The 2 liters actually worked exactly how I intended them to, even with a slight bonus, because if I staggered them in pairs left, right, left, right...10 fit perfectly in a tray, and they locked each other in tight, so I could make/move a tray at a time without having to worry about any falling over or out...which is obviously desirable