Spindly clones from marijuana mother plants

A question from a fellow grower:

My ph pen broke about a year ago and I just though I would guess at it. This was a big mistake so I went out and bought a ph pen and a TDS pen today. This is the fist time for me to buy seeds. I always got clones from other growers. I did get some BC Blueberry though you but i have a problem. I grow 3 mother plants from the seeds and what happened was after cutting over 50 clones and then bringing them to bud I have some that are just fine and some that are really tall and have a very spindly buds. never seen this before. they are 4 wks old. i was wondering if i should pull them out as they are not even sticky ???

It is very hard to know why without knowing a whole lot more about the spindley plant’s environment during the entire grow, as well as the current complete parameters, especially pH and nutrient strength/concentrations(i.e. NPK ratios and or EC/TDS/PPM). Spindly plants are usually the result of not enough light or not enough nutrients and sometimes both.

With your pH pen broken maybe those plants are suffering from some nutrient deficiencies due to a pH lockout? Or are these plants getting less intense light for some reason?

Also when growing from seed, you will notice some phenotype variances. It may be the mother these clones were cut from also is a little more spindly than the other mothers, just a thought.