im sure you will figure a way to drain, go to home depot ect.. and look for something shallow that you can fit under your trays (cement tray, shower basin, under the bed storage tote ect...)
my advise is to use the big pots (maybe 7 gal.?), but start in a small ones and work your way up 2-3 times to assure a proper root structure.(maybe start in 1/2 gallons, then move to 2 gallons, and then your final size 7 gal. pot... but try to be done transplanting by the time your plants are flowering.
growing large plants indoors can be tricky, so i wouldnt go too big since you are new to this. remember that most plants double or even triple in size once you switch the light cycle to 12/12....
to avoid problems, buy the correct gear and stick to your feeding chart and dont recycle the nutes.
i would try to top the hell out of them while in veg, and remove the bottom 1/3 of the branches and tie them down if you can. You want round bushes, not tall xmas trees.
i highly recommend Canna Coco and their coco nutes.
I almost have it all figured out. I bought the 4'x4' trays today and just used some landscaping blocks under them and put in drains. I am going to run the drain line out of the room..now I am not sure what to do with the end of the drain..just let it run under the house or tie it into the sewer line( which I am afraid I might get gases back into the room if I do)
Anyway here are some pics of what I got today and some pics of my drainage location.
Pic 1 - The pressed coco is for the trays, the bad is for the pots, you can see I went with 5 gal smart pots, and the rest is the nutes
pic2 - is the tub set up
pic 3- is the wall that I will be running the drain hose trough
pic 4 - is a pic of the wall so you can see what is on the other side
pic 5- is more of the drain area I can use including the sewer drain I could tie into
pic 6- is a pic from outside the room..I haven't put the door up yet
I spent 2 hours with my friend a the hydro store today and this is the plan- fill the tubs with about 4" of coco and inset 5 gallon smart pots with the premium coco..the roots are supposed to grow through the smart pots and spread through the tubs. I re-measured the height with the tubs set up and I have about 55" to the highest light positioning..the hoods will be vented with glass so I should be able to get about a max of 48 inches of plant.
This room is under my house..my house is bult into a hill so there is a lot of space unde there.
I am thinking I will just drain under the house for now .. it should just soak into the dirt under the house
Let me know what you think