Advice on new grow

Hi I'm thinking of doing a grow with subcools super soil in 20ltr airpots in a 3 x 1.5 x 2m tent using 2 1000w lights with 6" cool tubes. I was wondering how many plants I should do without overcrowding? and if I veg for 2 weeks in 6ltr pots then transplant into the 20ltr airpots half full with super soil how long should I carry on vegging to get a nice root mass before budding? I'm thinking of doing big bang as they're meant to be 9 weeks but my friend has lemon haze and cheese cuttings so not sure which to go for any input or advice would be much appreciated. Also should I ph my water with super soil? I'm using bubbled tap water which is normally 7.6-7.8..

Don't bother PHing with organics, especially a super soil setup. The vegging duration is up to you, but I usually veg to maturity at around 4 weeks or so. The plants can probably go for about 2-3 weeks in the 6ltr(like you said) before you will need to transplant into the 20ltrs. You can go about 2 square feet per plant, but you might want to leave an edge clear so you can get around to the back without moving a bunch of shit. A lemon haze will take a lot longer than 9 weeks I would think, I would go for the cheese cuttings myself for the first grow.

Ok cool I just finished some big bang autos in a smaller tent it's still not ready to smoke so not sure if it's any good.. I like the way it grows small and bushy I won't be doing autos again and not sure how cheese or lemon grows if it will get too tall? Was thinking of trying super cropping too.. Was thinking maybe 10 plants you think there will be enough room?

I heard it's good to have ph neutral (7) with super soil or 6.5-7 I will have some ph down left from last grow, will it hurt to ph down to 7 or should I just leave it completely natural?