Could this be light stress?

[bmuggle81]

Petiole turning purple only on the light facing surface. Spider farmer sf g3000 hung 26in at %28. humidity 48-58. temp 75-80 day/ 63-70 night. Overall plants are healthy.

 

[NairnM16]

It’s not light stress,
Super common I wouldn’t worry about it

Plants stems go purple when they are stressed
Could be to cold
Could be Improper ph
Could be vpd

Is your pots on the floor could cause the root zone to sit colder than the room

But I wouldn’t worry focus on the leafs they tell you everything you need to know

 

[Glomus]

looks healthy af if anything could use more light

 

[delps8]

Agree with @Glomus on both points — healthy plant and needs more light.

Cannabis will grow in light levels between ~60µmol and "800-1000"µmol. Growers generally go with 300 in seedling, 300-600 in veg, and >600 in flower.

With that light at 26" and 28% the plant is getting very little light, my thinking is in the 300µmol range. Cannabis plants that have received a low level of light since germination will be tall and slender, with a limited number of branches and leaves and the leaves will be larger than normal.

The recommended hang height + dimmer settings about half way down this page are typical manufacturer settings and manufacturers, across the board, tend to be conservative. It's not easy to get a good light cast at 12" so I'd go with a higher hang height and bump the dimmer setting.

A cannabis plant of that age will tolerate increasing light levels far more quickly than the grower will. :-) Assuming that there are no issues with the grow, you should be able to increase light levels in a couple of days.

Pictures of the plant and the grow tent would be interesting to see.

 

[mancorn]

Some strains/pheno are just purple. Both of these plants are the same strain, but one pheno shows lots of purple in leaves & stems.

 

[Glomus]

Agree with @Glomus on both points — healthy plant and needs more light.

Cannabis will grow in light levels between ~60µmol and "800-1000"µmol. Growers generally go with 300 in seedling, 300-600 in veg, and >600 in flower.

With that light at 26" and 28% the plant is getting very little light, my thinking is in the 300µmol range. Cannabis plants that have received a low level of light since germination will be tall and slender, with a limited number of branches and leaves and the leaves will be larger than normal.

The recommended hang height + dimmer settings about half way down this page are typical manufacturer settings and manufacturers, across the board, tend to be conservative. It's not easy to get a good light cast at 12" so I'd go with a higher hang height and bump the dimmer setting.

A cannabis plant of that age will tolerate increasing light levels far more quickly than the grower will. :-) Assuming that there are no issues with the grow, you should be able to increase light levels in a couple of days.

Pictures of the plant and the grow tent would be interesting to see.

Yeah probably why people end over feeding too, as plants will uptake more nutrients with high amounts of light

 

[SmallspaceGrace]

Anthocyanin pigments express in many plants .. have found its most prevalent in the more indica leaning phenotypes
nothing wrong with your girls at a glance .. Have found them over the years to be prone to being fussy with nutes though.