I don't know if there is a size limit with these things, you can literally grow TREES ... in soil, I always grew 6-8 plants at a time in my cabinet, now I can easily blow the doors off with ONE plant :thumbsup: ... a local hydro store has a full-grown palm tree, complete with coconuts, in a big hydro tub :wtf: ... I found mine have much more capacity than I really need ... add a big airstone to each container, really helps growth, and fights root-rot ... :thumbsup: