On my first grow, and after all the research I did prior, I still screwed the pooch on nutes, however, not catastrophically...yet.
The advice I followed that is working well so far:
1. Keep it simple.
- I went with dyna gro nutes because it is an all around nute, and it is working well. 1 bottle to add for grow, and one to add for bloom. Easy. I've read where other grower use the same simple approach with a variety of nutes, and I'd highly recommend going with a simple approach. Look for K.I.S.S. threads.
2. Start low and work up.
- I started using quarter strength, and slowly worked up. This approach works well because you can always add nutes, but you can't undo damage caused by over nuting. I'd rather add nutes than flush a plant, and if you go too far, even a flush won't undo it.
3. Take and keep notes.
- Keep a log of temps, humidity, feed and waterings, how much, PH, etc. It helps me as a n00B to learn what is working, and what I need to fix.
Things I learned on the fly:
1. Be prepared to make changes according to YOUR environment.
- Everything from frequency of watering, to nute strength, and frequency of feeding will be influenced by YOUR environment. Be prepared to adjust.
- I failed to take my environment into consideration when I started feeding my plants, and as a result, I accumulated nutes in my media (coco), which lead to nitrogen abundance in two of my plants. I vegged under a 2ft 4 tube T5, which doesn't supply the plants with as much energy as a bigger light (MH, etc...), and by following the feeding schedule of grows done with more intense lights, my plants had more food than they could use due to lack of light etc....
2. Let the plants tell you what they need.
- I read this advice before I started my grow, and it is a learning curve that I am still trying to get a handle on. IMO, this is the best approach to both watering and feeding, but must be learned by experience. The plants color, leaf shape, and "attitude", will all indicate whether they are "happy", need water, are over watered, or need food. Experience is the only way to learn these signs, so look for them, and take notes.
In the end, no matter what nute you go with, you will have to make adjustments to meet YOUR growing environment and conditions. Fortunately, cannabis is a pretty damn resilient plant, so even n00bs like us can keep them alive as long as we don't fuck up TOO bad, and if it gets bad enough, forums like this place can help us out.
Good luck on your grows!
