7 gallons u won’t need to transplant and should have enough soil charge to get thru veg. U may fall a little short on light. With that size space maybe u can minimize it by putting something reflective on the open side to lessen the lights footprint. Water only the area of the soil where roots may be. U don’t want to water soil not being used.
I read a lot on here of people washing soil Bc it’s to hot but then why pay for those nutes to b in the soil if u r going to go home and wash them out. Let your plants dry out before watering. It’s good for them. U will get a feel for the weight of the pots to know if they need to b watered.
What I meant by reflective on the open side was. If u are only flowering 4 plants in a 6x4 u won’t b using the whole space. Use something to make your space smaller. I have 2 plants in flower in that same size room. They obviously aren’t taking the whole room so I do this
Makes a smaller footprint for my light to illuminate and gives my plant a closer reflective wall to bounce light off. Ever wonder why buds closest to the walls are best? They like reflective light
I’m not worried about the footprint, other than needing about 40-50 real watts per square foot of light for flowering. With some LST and SCROG plants take up as much room horizontally as you make them. I’m worried about the height. With these big pots and “letting them veg a long time” you could outgrow your tent. The pots are say 12" high and you need say another 12" for the lights and distance from the lights. That leaves 80-24 = 56" for plants. Most strains stretch x2 or x3 after you switch the lights to 12/12. That means you can only let them veg until they are about 20" tall! That’s the factor you must deal with or your top buds will hit the lights.
Not a problem with autos: They start to flower so soon, they don’t get that tall. But photoperiod plants can veg forever and turn into trees.
Now I need some help… Planted seeds 5/12. GL fem. Germinated 5/15. Is there something wrong with these 2 side leaves? I planted another stash seed same time. It germinated the next day and looks good. I will try to attach pictures