I feel glorified.
This is my first grow.
But I do know my tech stuff!
Q1 : the soil : general potting soil for flowers. 40 liter bags cover these three pots. I bought them at the local DIY shop. I germinated in this soil. Very easy to over water. Will kill some seeds because they can't handle the soil. That's ok. You want to go with
THAT WHICH SURVIVES. Meaning something that is in 'balance' with its enviroment.
Q2 : the light/photperiod. First 3 whole months of vegging on 17/7. Then every day -1 hour of light until 12/12.
Q3 : the maming :
the general idea here is to increase biomass exponentially. I've noticed how trees outside who are split-stem just a few foot above ground grow the fattest stems and the most biomass. I love trees. They are my great example for growing grass.
Basically you can cut off the top once the stem starts alternating nodes. Wait a while until you see the two shoots come out from the highest two remaining stem nodes. Wait until they get decent fan leaves.
Cut off the fan leaves. Not all of them. Just the ones that block the light going further down to where nodes meet the stem or new shoots. Wait until it has recoverd so the leaves are just as big as when you just cut the off.
Cut off the tops. Whipe them out. All of them. Never let a single top remain unless you decide to stop cutting and flower, you don't want to introduce serious assymetries since this reflects how the plant spends its energy. There are now at least two tops probably more since you've been busy cutting fan leaves. After choppin' heads wait again until decent fan leaves appear.
Chop chop with the fan leaves and so on and so on.
Only theoretical limits I see :
1. Maximum age for your plant which should be around 9 months. This includes flowering. Who ever you are and whatever you do eventually your plant
WILL DIE. Thats' ok. Just be ready.
2. Size of the rooting system. Pots are limited in space unlike the earth around trees, practically speaking that is.
SO ABOVE SO BELOW! I know it sounds like a boring bible passage but if you imaging a upside down marihuana plant sticking into the ground just as big as the one you can see above ground it kinda makes sense. This is about the ultimate above to below ratio.
If this above to below ratio goes awry you get problems with soil contraction because you HAVE TO water every day and when you come back the next day the soil is bone dry and thus smaller. Also a common problem then is nute burn due to excess nutes in the soil. If you add 2 liters of water to a 10 liter pot every day you will have this problem.
3.Plants go psycho after all that torture. Meaning herbie. I see this as evil. So unnatural. In actuallity you are helping the plant become big and strong! Also, if you find a plant that likes to be cut you can clone it. It probably likes that too.
Ofcourse this all assumes you have taken proper care of the light, the wind and the heat and so on to begin with.
But ofcourse you should ask others too, I'm just a growing sux0r n00b, but I do know my tech stuff...