Hi everybody. It is currently May 18th, 2020, and I am updating this diary retroactively. As I write this entry for Week 1, I'm actually on Week 9 of this grow. As such, I'm able to comment on where I went wrong during the first 7-8 weeks. Hopefully anyone reading this will be able to learn from my mistakes. This is my second grow; the first of which was cut due to a training-attempt catastrophe so I started over. To be honest, this time around was much rockier from the get-go.
I currently have a very stunted plant that I contribute to two primary failures on my behalf:
1. Light Stress:
I decided I wanted to use a lux meter to measure light levels. I foolishly found a resource online telling me that, lux levels required are roughly as follows: 20,000 for seedlings; 40,000 for veg; 60,000 for bloom. WRONG! While lux meters can be useful, you simply cannot rely on numbers given in this simplistic fashion online. There are too many variables. If you chose to use a lux meter to help you out, you'll need to calculate/experiment and develop your own lux parameters. One thing to realize is that lux is a measure of light intensity. It can be converted to PPFD, which is a measurement of how many photons hit a certain surface area over a period of time. The key word there is TIME! As such, your light cycle will influence your desired light intensity, whether it be in PPFD or lux. If you look up PPFD recommendations for cannabis, you'll find numbers like this: 150-300 for seeds, 300-600 for veg; 600+ for flowers. BUT! These numbers assume a 18/6 cycle for seeds and veg, and a 12/12 cycle for flowers.
For this grow, I chose a 24/0 light cycle. In doing so, I should have reduced my light intensity, as the numbers I'm aiming for are based on time! A plant running on 20/4 can get by with a brighter light than a plant running 24/0. I failed to consider this. In any case, I found an online calculator to convert PPFD to lux, which depends on the spectrum of the light. I'm using a 3500k QB LED (135W). I was able to find that the 150-300, 300-600, 600+ PPFD values correspond to lux values 5000-16000, 16000-32000, and 42000-58000. But again! This is based on standard photoperiod light cycles. Accounting for my 24/0 cycle, these numbers should be scaled to 4,000-12,000 lux for seedlings; 12,000-24,000 for veg; and 21,000-29,000 for flowering. Again, this is for my current setup.
In short, my plants have been getting TWICE as much light as they should be.
2. Overfeeding
I also ignored readily available advice and gave my autos full-strength nutrients starting in week 3. Well, sort of. The instructions on my GH nutrients say to feed with plain water every second feeding. I simply decided to feed my plant 50% of the recommended nutrients, but I fed nutrients each time, with no intermittent plain watering. Alas, I started seeing early signs of nutrient lockout mid-flower, and decided to flush it.
So, enough of the preamble. Onto the diary.
WEEK 1
You can see the light burn on the seedling. Growth pretty much stops at the end of Week 1.