low potency

So I ordered some of Nirvana's Jock Horror and Northern Lights, feminized. Grew them, smoked them and was so unhappy with the potency.
Everything else was great: nice vigorous plants, good yield, dense nugs, lots of resin, great smell - but very, very weak. I read people get high with just one toke of Jock - I have to smoke a WHOLE big joint by myself, to get some effect. Same is true for friends (and family). It lasts for a longer while, that is true, but I've had much more potent plants from bag seeds.
Now, I am not a novice grower and I think I grew the plants just fine (if anyone wants, I'll try to post some photos). I did burn them a little bit (hi temp), but I'm just finishing a second round of the same plants (cuttings) that hasn't been burned at all, and the samples show the same lousy potency.
Another possible problem, before I start blaming genes, is my lighting. I use a 400W HPS, a Philips bulb, named SON-T Pro. It was the olny thing I could find. I am pretty sure it is a "basic" HPS, (unlike those sun-agro types) that doesn't have much on the blue side of light. I read that blue light (and ultraviolet, etc.) is important in THC production. Now my question is: HOW IMPOTANT? What are your experiences? Do you think that the same plants grown under the two different lights (regular HPS vs. HPS with added blue, or cfls or MH or whatever) could show THAT much of a difference in potency? I used to grow with CFL's and floros up until this grow, and this is my first time HPS as well as first time brand name seeds. I discontiniued my previous plants, so I have nothing to compare with. I will probably figure this one out this fall, when my outside clones finish, but I am getting impatient. I would like to hear some thoughts on that.
Genetics. Could it be that I just got lousy phenos? Bad luck. OK, I can live with that. I produced seeds, so I'll try my luck with some of the offspring, the genes should be there somewhere. Right? Well, I hope so. But the fact that the six plants that I grew (3 NLs and 3 JHs) didn't show much of a difference in anything (none of them got me decently high) makes me wonder, wonder...

Any thoughts? What do you think could be the cause of the lousy potency?

Thank you

I had the same thing happen with my Nirvana Northern Lights. On mine, the pH was too low, like in the 5's, and it got a lighter weird green color for a few weeks in flower. It does get me high and smells half way decent, but I won't be growing it again. Maybe I messed it up, but genetics have a part to play as well.

Now, my Strawberry Cough was the premo of my last grow. A shame it was the lowest yielder. But I digress.

Resurrecting this thread. I just grew out Blue Mystic, 8 weeks harvest. Trichs mostly cloudy. I had a low potency problem with Nirvana before, Hindu Kush.

are you a heavy smoker? because i used to get high off one hit now it takes a whole joint. and maybe its just bad luck not all plants have the advertised potency just keep searching strains and make sure its dried and decarb'd and cured well.


i grew out white widow from nirvana and it was good smoke from the 3 females i got out of the 10 seeds.

Just not a very potent geno, but still should taste really nice.

I would chalk it up as lousy genetics, nirvana is known for their Chrystal and Ice.