Plants Keep Falling Over

[jonb]

I have two 8' x 4' flood and drains tables in my flowering room. Some plants that are over around 2' (+ 6" basket they are sitting in) and even a one or two smaller plants seem to lean over. The smaller ones just lean over but the larger ones topple. It can't be good for the plants to keep falling over like that not to mention it's a pain in the ass to pick up all the hydroton.

I have temporarily stopped them from falling and leaning over by using strings from the ceilings to keep them standing but I can't do this for all the plants. Is there a reason these plants are leaning to the side and off balance? How can I fix this?

[StoneyJake]

Do you have a rotating fan in your grow area? That helps thicken up the stems a lot. It hits them with air every few second and moves the plant slightly like its out in the wind. The plant anchors itself better so it doesnt fall over.
You might have to string it up once the buds get heavy depending on the strain. For sure with this plant

[FaderVader]

Requesting pics to further diagnose.