I ask because a lot of those seedlings look pretty close together in that thing...
Which means that when they are big enough to transplant you will have to tear some roots...a larger plant will recover better than a smaller plant, but the larger the plant the greater the damage...But if you are putting them outside then leave any that are close together, still together...then once you are putting them outside when you bury them just kinda pull them apart but leave their root area together...they have limitless dirt in which to grow, and all the space they need to stretch away from each other...but if they are indoors you need to move them as soon as possible to separate homes, or put 2 or 3 in 1 huge pot, but 6 in a little bucket just won't do it...and also remember, that when you have more than one plant in a pot, those 2 plants will usually end as large as 1 plant in same pot would do, and the yield is equal to 1 plant in 1 pot...so both plants end up stunted but they will grow and all that...but something to think about...and to me it seems that if you had a large enough tub, or pot that that wouldn't have to be the case, as long as you remembered to nute based on amount of plants as opposed to amount of water...seems you would have to overfeed per gallon, to make sure that all plants would get enough...but one pot will only hold so much water...anyway it would be a huge hassle...I will grow 2 totally different plants together in one pot...like---ummmm...I grew some indoor tomatoes with catnip all around the base of them...but even if both plants suffer a little it doesn't really matter...I have a bunch of tomato plants, and the catnip is for the cats...so eff em...I would worry with more than one Mj per pot though...I have read through quite a few grows here where someone was doing the same and you don't end up with double anything, but each plant gives half...