4 main colas is good, but imagine 10+ big main colas per plant. With the proper set-up in Hydro with a 1000 watt HPS it's quite easy. I use to top but switched to LST and SCROG, which is very similar to topping(sending growth hormone to other branches). First harvest using this method with 2 Northern Lights plants i harvested over a pound and a half dried bud with Main Colas weighing a ounce+, all in my journal. Topping took longer in veg. for me and since I switched to LST and SCROG I haven't looked back.