I think the .8 gallon air pots are the most versatile size (great for 12/12 from seed, most autos, 1 month veg SOG, etc). Only issue is you may get to a point where you have to water them once every 24 hours! I did a 1 month veg with .8 and 2 gallon airpots, definitely more impressed with what the .8 gallon did with their size ( I think the 2 gallons need at least 6 weeks of veg, maybe 8 or more). I have a some Mykos in mine, my biggest plant seems to need 32oz every 24 hours in its .8 gallon airpot