You are wrong my freind.
I’m sorry you had bad experiences with other forums but that’s not what we do around here.
We genuinely try to help each other and do an exceptional job most always.
I’ve never read a cannabis book in my life, I learned most everything I know from asking people on this forums and youtube and I’ve definitely learned alot 
No one is mad about you doing what works for you but rather you come across very aggressive and as pointed out, also aragunt…
And the simple truth is, you are incorrect my freind, horticultural has came along way since Ed Rosenthals time, and if someone relies only on his information, they are not going to compete with modern technique growers…
Ed Rosenthal was one of the pioneers of cannabis cultivation literature, and while much of his advice from the 1970s and 1980s was groundbreaking, some of it has since been updated or corrected due to advancements in cultivation science. Here are a few things that were once considered best practices but are now seen as inaccurate or outdated:
- HID Lighting & Spectrum Myths
Early editions of his books often emphasized High-Intensity Discharge (HID) lighting (like HPS and MH) but didn’t fully account for how modern full-spectrum LEDs could outperform them in efficiency, spectrum control, and heat management.
He also promoted Metal Halide (MH) for vegetative growth and High-Pressure Sodium (HPS) for flowering, but today, many growers use full-spectrum LEDs throughout the plant’s life cycle with better results.
- Overemphasis on Soil Amendments & Organic Nutrients
While organic growing is still popular, some of his older writings suggested that heavy soil amendments and composting were the best way to optimize growth. Today, hydroponic and soilless growing methods (such as coco coir) are often preferred for precision feeding and higher yields.
He also didn’t emphasize how salt buildup from organic amendments could cause nutrient lockout—something modern growers manage carefully.
- CO₂ Enrichment Misconceptions
Early cultivation books, including Rosenthal’s, often suggested that simply adding CO₂ to any grow space would boost yields. However, we now know that CO₂ enrichment is only effective if all other factors (light intensity, nutrients, temperature, etc.) are optimized.
- Pruning & Defoliation Approaches
Some of Rosenthal’s early work advised against removing fan leaves, arguing that they were crucial for photosynthesis. While this is partially true, modern techniques like strategic defoliation, schwazzing, and low-stress training (LST) show that selectively removing leaves can improve airflow, reduce mold risk, and enhance light penetration for better yields.
- Seed Gender & Hermaphroditism Misunderstandings
In early cannabis literature, including Rosenthal’s, there were misconceptions about how to determine and control plant gender. Early advice suggested that environmental factors played a dominant role in sex determination, whereas we now know that genetics are the primary factor.
Hermaphroditism was often blamed on stress alone, but we now understand that some strains are genetically prone to herming regardless of environmental conditions.
- Nutrient Feeding Schedules & Ratios
Older guides often recommended heavy feeding schedules that don’t align with modern nutrient science. We now use more precise ratios based on plant growth stages, using tools like EC meters to prevent overfeeding.
The idea that flushing with pure water at the end of the cycle significantly improves bud flavor is also debated today—some argue that proper nutrient balance throughout the grow is more important than a flush.
- Drying & Curing Techniques
Rosenthal’s early books often suggested faster drying methods, but we now know that slow drying (60°F–70°F at 55%-60% RH) and proper curing significantly improve terpene preservation and flavor.