so there are eight plants per 4 foot pole. Each ofset on 2 of the four sides on a diamond angle. Theese are 2 foot from my light pole cool tube thing I made. The plants are doing good but the probllem is the top 2 in each pole are not getting enough light. I will need either higher wattage or add another section. If this goes well we change all the systems for the dispemsary to this kind of system. I will however probably steel the round pipe idea instead because my system tends toleak from the net cup holes from time to time no big spill just nutes traveling down the front of the poles back into the res. I have it on a 15 on 15 off drip from the top down.