Long Red Cayenne Hot Pepper

I picked up an heirloom variety of the cayenne pepper on a whim, called a "Long Red Cayenne." The intention was to see how it would do on the balcony, but that level of patience does not suit me apparently.

Enter spacebucket.

Spacebucket.

An adjustable LED power supply drives a 100W white LED array, while the PSU powers a 12V LED power strip for side lighting and fans for airflow and cooling. The inside is covered in aluminum foil. There are a lot of things I would do differently on a rev 2, but it works.

Day 1. The LED adhered to the heat sink by a thermally conductive epoxy. Side lighting is too high, main LED is too low. 

Re-potted in a 1-gallon pot and beginning training. Since it's in a small bucket, I do not want the plant growing straight up. I'm thinking it would be cool to spiral the stems around if possible.

Day 2: The Re-potting 

Half a day later and the stems had already righted themselves. A day later there is some noticeable growth as well as some purpling of the stems and edges of the leaves.

Day 3: The Purpling

Closeup 

I've read this can be due to many things. Too much light, a deficiency or low soil temperature. I also saw a mention of high winds causing it for one person. Fortunately, all three of these are very possible in this setup so I need to experiment.

• I am currently running the lights 24/7, from what I've read this leads to bigger plants without ill effect. Some plants require a rest period but peppers do not.
• No fertilizer has been applied. However, it is fresh high quality soil, so I am thinking this is less likely. 
• I haven't measured it, but due to the low ambient temperature (generally around 65 F) and the high air flow against moist soil, I expect the soil temperature is lower than the 75 F that it probably is looking for. 

First, I am going to wait to see if the problem gets worse or if the plant shows any other signs of stress.