I enjoy cannabis since teenage (I'm 30), traveled to smoker's destinations across Europe, bought hash in Maroc, read tons of books about cannabis and cannabis cultivation, constantly looking for opportunities to improve knowledge about the plant. And I love to get stoned.
About half year ago I started indoor cultivation, now I'm during second harvest (DutchPassion Automazar and Think Different).
Potency is disappointing, but I found great joy in cultivation itself. I realized that THC content is not that important when you have own dope. While growing I train soft skills (patience

, relax working in garden etc. Savings are also great.
I decided to stick with cultivation and looking for ways to improve gardening skills (and zen of growing

.
My plants are mostly healthy, vigorous, yield a lot, but potency and smell is an issue. It's just not dank comparing to high quality street weed, and not even in pair with stuff I got in Amsterdam or Prague. They are a lot weaker than shit-quality buds bought here (they taste much better though).
Grow room: 60x100cm (2x3 feet)
Lights: 600W HPS (Lumatek digital dimmable) and 400W MH (GIB) in Sputnik air-cooled reflectors (separate from main vent). 4 additional UVB Repti lights (4 different brands)
Vent: Separate 800m3 vent with carbon filter. There are 3 additional ventilators and 4 repti-glo uvb lights. i
Medium: BioBizz/Canna soil, Canna COCO, Local mixes.
Fertilizers: Canna fertilizers, Rhizotonic, PK13/14, Booster
Additional: RO water, EC and PH-meter. advanced weather station
Grow temperatures are 23-26C (70-80F), humiditiy around 50-60% during veg, lower during flowering.
As you see - more-than-enough of light, great ventilation, good nutrients. No mold or pests problem.
Plants are 16 weeks old (dutch passion says they should be ready by 10-12 week).
I was running 24/0 18/6 and last mont 12/12. Trichomes are milky, 5% are amber since 4 weeks ant not changing colour anymore).
I got 8 plants, so I harvest them from 9th week periodically and partially checking potency (no quick-drying). Weed tastes nice, but not really skunky, and I have to smoke 3-5 joints by myself to get high. Friends with lower tolerance are stoned with 1 joint, but sharing a joint give a little effect. Effect (even water bag hash ) are rather subtle (no big "hit" and "stoned" feeling, more like mild disorientation).
Same with 1'st crop, seeds where from some femaleseeds.nl autos.
A friend of mine is growing other straing with a lot worse equipment, but similar results (not potent weed). I though that's beacuse of his lack of intense lighting are ventilation, but results are really similar.
I assume lack of potency is caused by them being autos, little hermie (like 30 seed total), earlier lack of potency i- not enough light (400W HPS for same area) so now I am going 12/12 with 3 moths old DP Blueberry photosensitiv in hope of getting something really strong.
What skills should I improve to get better results in term of potency and quality? Is it in proper-nutrients? Or should I take more care about pruning? Or I just need to grow many plants and take clones of best, as it's very rare to get killer weed from commercially available seeds? Or I am out of luck with genetics? OR should I try to understand the plant and the results will come (which I am doing)?
Dont get me wrong, I enjoy my crop, I just dont know how come even cheap street stuff is more potent than my well-cared and cured weed?