Hydro set-ups are popular because they produce many small plants that finish quickly. They finish fast because the plants are exposed to
water, air and nutes almost continuously. Dirt produces larger plants as a rule that take longer to finish. I use dirt as it is much easier. Until
you really know what you are doing stick to dirt and avoid all the headaches associated with hydro set-ups and flow tables.
Which strain you use is the single most important factor in finishing time. Some sativas need 10+ weeks of 12/12 lights to finish flowering.
I seek out autos (autoflowerers) and indicas that have been genetically modified to finish fast. Some indica/ruderalis strains are done after
just 8 weeks in dirt. I get most "big bud" types of indicas to finish with 4 weeks vegging and 4-5 weeks flowering. By finishing in 9-10 weeks
I can grow up to 5 grows a year.
Also, using small pots of less than 2 gallons or so will tend to keep plants smaller and therefor faster.
BigSteve.