How do you keep your plants suspended and not teeter-totter?

Hello,
I'm in the midst of my first aeroponics grow, the plants are looking most excellent. I built this aero system using a plastic tub with a pvc manifold. The drain water drains out of the system tub into a separate reservoir. Due to heat issues, I went with LED's. Humboldt nutes. RO water. 396gpm pump.
I started the seeds in rockwool starters, then placed them in the center hole of 5" net pot lids. Once they germinated and grew some roots, I put them in my system, no net pot, just the 5" lid dangling the roots in my tub.
My tallest plant, the most beautiful LSD a person could want, is about 16" tall. When I got up this morning it was kind of laying over to the side. It's like 'hinging' right where the plant goes through the rockwool, through the lid, there isn't anything holding it. It's like a teeter-totter standing straight up, pivoting in the middle, the roots being one seat and the top of the plant being the other.
How do you 'suspend' your plants? How do you keep them stable? Now I'm kind of freaking....what if they like fall through or something? Like a hippie bugs bunny in my tub pulling my plants through.
Any help would be greatly appreciated!

ive seen some people cut a slit(halfway across) in a circular piece of foam or such.. and place your plants stem into the slit, while the foam is resting on top of your system. This should help to hold it up

i use fish line and curtin hooks..works great.

A netpot lol. They're gonna fall through that lid when they pack buds on, live and learn meanwhile tie em up

+1 on netpots...problem solved!

Thanks much for your replies. Once my seedlings had some root growth, I put them in my system, with 5" net pots. They started drooping and looking really crappy, so I figured they were starving for water and pulled out the net pots and they have been flourishing since....well up until the day Ms LSD kinda fell through, but no harm no foul. That's why I didn't use net pots, but what you are saying is since they now have this bodacious root growth that they wouldn't starve in net pots? Which brings up another thing, I thought the whole deal with aeroponics was that the roots are exposed, no nothin', just like hanging there looking all cool. Do you all use net pots? I've seen pics here showing unencumbered root growth, no net pots. What do you put your germinated seeds in to root? Thanks, man.