Ebb and Flow can a tray be Root bound?

So i had like 4 plants growing in a 15.5x11x5.5 inches, and my roots got bound, and now i am dealing with root rot in the flowering period because of drainage issues.

So im thinking it should have been 1 plant per grow tray? Doesnt that defeat the purpose of a Ebb and flow grow tray?

What could i have done otherwise?

Not the best photo but it should give u guys an idea

This is what i am dealing with, broke off most of the root web inside the tray when i pulled this stalk out, got like 50 perc good roots and 50 percent bad roots. However i’ve done a complete clean with bleach solution and soaking of roots. Wish me luck.

YES! I have a supercloset or something and my plants start rising up on the roots because the tube/tray isnt deep enough. Started growing last April 1st and have made several modifications after getting root rot. 1st is pitched tube/trays back to the tank so they fully drain in-between cycles. 2nd- lay a piece of .5" or bigger tubing in the tube because the roots will totally block off any nutrients from flowing to the end of the tube. 3- Add more air stones! I have 12"×1" stones in the tubes. It really helps. Fresh air inbetween feedings with them too.
Going to switch eventually to aeroponic.

I’m using trays, now i’m experimenting with fabric pots filled with hydroton, just like an ebb and flow bucket system but slightly unconventional.

Btw if you are using pipes, how does adding a .5 inch tubing help? Does it have holes in it till the end?

It’s a trough type system with 5 4" baskets in each. I just lay a piece of tubing in the bottom to give the solution a way past the root system of the first plants because the drain and fill are next to each other on one end. They act like a mini Hoover dam.