Well these girls seem to be heavy on the indica side 80% and staying short so far I am thinking topping won't really be necessary but if I am going to top I should do it soon any opinions on the matter would help I have plenty of space including headroom these are 3 weeks since sprout
see whats going on here is you are using a Mh light thats uses 6500k approx., colored lighting the color of the light shapes the plant you want short squat plants with close internodes then continue growing but about this time, to use the 2700k HID the color(red) encourages the internodes to widen and grow pine tree shape, as it is, squat plants tho low and great to grow in a shoebox get more mold due to the lack of air in and around the plant leaves, once you got the right shape and on about the 3rd or 4th lateral then yeah trim away unless you like whirly-whirly roots I'd stick to standard round plastic, watching close good luck ps that bulb does look like the conversion lenses of the 1970s great value today but low Lu (30K lumen?)
Says 90,000 lumen I have the red spectrum hps lamps I was going to switch pretty soon I didn't want them to stretch yet