The root development will dictate how long you can leave them in the tote. Once the roots break out the sides of the netpot you`ll struggle to get the netpot out of the tote without damaging the roots. Trying to shoehorn the netpot back into the larger system will be even more difficult as you`re pushing roots rather than pulling :)

One workaround is to mount the netpot in a plantpot saucer and size the holes in the system for the saucer. Move the complete saucer/netpot combo over to the larger system. If you buy extra saucers, you can use a range of netpot sizes in the system or even multiple netpots in one saucer for cuttings or small plants.

Thank you for the response hex. I think I should restate my question. I dont want to leave the plants in there as long as I can since this tote will only be holding a weak nutrient solution aimed at growing seedlings. So I suppose my question is: when should I transfer the plants to the stronger nutrient solution? Is there a way I can tell if they are beginning to require more nutrients?

Tracking the daily ppm and ph changes is the best way to tell whats happening with the nutrients at any stage.

Ok. I have been monitoring them daily. The pH is pretty stablr and ppm rises a little bit everyday. Does this mean the plants are pulling more water than nutrients? Will there be a noticeable drop in ppm when the plants are beginning to pull more nutes? Thanks for all the help.

As long as the ppm isnt rising excessively you can just add plain water back to maintain the original water level to keep the rise in check. If the daily ppm rise starts to outrun the plain water addition, its best to reduce the overall nute strength.

Ok, great. And thanks again for your help.

no worries,
the seedlings look a little on the yellow side in the pic, maybe they`ve greened up since? If not, make sure the water level is 3/8" - 1/2" below the bottom of the netpot. The bursting bubbles will keep the pebbles plenty damp enough.

Yeah they were a little yellow starting out. I was under the assumption that the water should be slightly into the net pot, so I think I was oversaturating the rockwool. A while back I lowered the water level like you suggested and they are really starting to take off and get that nice dark green that I am looking for.