Rapid Rooters

I have a question about rapid rooter plugs..I started some seeds about 3 weeks ago and they are doing great..About 5 inches tall and healthy..Im using clonex solution in bottom of tray...I cant move some of them for a couple more weeks...How long can they thrive in those plugs with the roots in water in bottom of tray?....Thanks in advance...

once the roots start busting out you're going to want to get them into soil. if you leave it too long, transplanting will be more difficult.