White Widow with low yield and purple stems

This is my first grow. I started with germinating 4 seeds.White Widow (Fem). I planted the three that sprouted but only one took. I decided to just grow the one plant. I am growing in soil in 4 gallon bucket.Growing in 4x4x8 tent with( 2) 450 watt LED lamps (Spectrum King™ (SK450). Fertilized with Fox Farm Trio formula for soil (big bloom,grow big & tiger bloom). Vegged for 7 weeks at 18/6 lighting at about 60 degrees F before putting in tent… Switched to 12/12 and am 8 weeks in. Very few flowers and the leaf stems have all turned purple. I think I have been very careful about over feeding but some say the purple comes from that.
Plant is only about 3 feet high. I have no fans in the tent and although I have 6 inch ducting in the bottom and out the top, I have no exhaust fan. PH seems to be around 6 to 7. Because of my location in Alaska, the ambient temperature averages around 55 to 60 most of the summer. As weather became colder, I turned on the heat, in the building that the tent is located, to 60 degrees. The temperature in the tent was in mid 80s. I recently started opening the tent to cool it off a little. .
This grow has apparently failed but I want to start again as soon as I harvest but want to do a better job of it.
Is there anything I can do to save this plant? What should I do differently for next grow?
Any help will be very much appreciated.

Purple stems is often a sign a nutrient deficiency. It could very well be potassium in many cases. But if you are feeding the plant a good balanced nutrient that contains plenty of potassium, and most nutrient lines have more than enough, and your pH is in a good range averaging around 6.5 or maybe little lower in soil, it most likely is not the potassium.

Over-watering can sometimes contribute to a nutrient lockout and often red/purple stems are the resulting symptom. In a case like this it is more often a cal-mag deficiency, but the pH in the soil or the run-off will show a acidic pH well below 6.0 in most cases if it has been going on for awhile.

In most cases a cal-mag supplement will help and would be the likely remedy in a case similar to yours, where all the normal problems have been accounted for, a bad pH or a simple lack of the proper nutrients all together, neither of which is in your case.

Keep in mind, some strains are prone to purples, especially during flower, and also cold temperatures, at the leaf or at the roots can both also cause purple to show in the leaves and stems.

Hope this helps,


Thank you for the information.
I did have one problem related to over watering for most of the grow before I realized it. I am using a bucket in bucket approach to let the water drip out the bottom into the second bucket. I drilled drain holes in the bottom of the inside bucket and drain holes in the lower side of the outer bucket. I did not realize that my holes in the side were possibly a little high and the water retained in outer bucket was probably keeping the bottom of the soil wet. I will need to find a better approach for next grow. I discovered this when I bought a soil moisture meter and the bottom layer of the soil was way to wet. I have not pulled the 2 buckets apart, to avoid disturbing the plant, but I would not be surprised to see that the roots have grown through the drain holes in the inner bucket and into outer bucket.
When my lights go off, the temperature in my tent will revert to the room temperature which is 60 degrees F.(15 C) Is that to cold? I have recently ordered inline fan and thermostat for next grow so I can keep the temperature a little lower during the lights on period. The IGLM grow bible suggests ideal temperature of 75F (24C)

60*F is at the lower end of things, as long as it doesn’t get lower it should be fine. Yes, 75F is about ideal during the day.