:smoking: welcome to the steep side of the learning curve mate! You will do better next time for sure
it's not a simple as the namw "weed" makes it sound!
You have some good advice here,... and had some bad luck!
-- I have never been impressed with fucking Barney's, collective opinions I see are hit&miss with pheno's at best,.. avoid their lousy Sweet Tooth, what a shit show that one has shown to be...
Most of the companies you see here are well vetted, and do consider the smaller breeders like Twenty20Mendo, Gnome, Jean-O (1man gig, quality stuff), Night Owl and Dragon... If you are stateside, look into the seedbanks established here for better shipping odds and costs...
Gnats are a bitch, but can be beaten back pretty easily.. best work prevention side vs. curative though! A variety of products out there, some biological like Bt, nematodes,... organic stuff like frass (bug turds literally, nutritious too!),... Some homework to do there as well,...
--- avoid Fuxfarm soils, fair warning! Lucky are the few that get good batches, many get shwag full of debris, undercooked components, bugs and worst majorly off pH, talking low 5's here
- you FF! I ran Sick Bay for 6 years here, OF was the #1 problem soil hands down,...
Roots Organics has shown pretty well, Royal Gold King's Mix is one I use that likely fairly well distributed...
Now about "organic soil" and synthetic nutes, that's just fine... I'd say learning the nutes is one of the tougher aspects, managing pH, ppm's, in solution and in-pot! Trust me, sooo much hinges off the in-pot pH being in proper range! Getting your nutes pH dialed in before feeding is a big chunk of the battle,... To date, I like Prescription Blend nutes best, a smart 6-part system that is flexible enough to tinker and adjust if needed; 2 parts can be used as foliar treats which is an excellent way to boost your girls!
That said, going with a "water only" type soil, (not necessarily a TLO, true living organic) is a smart way to flatten that curve some! I have gone this route myself to eliminate the feed hassles with synthetics, and I wanted organics mainly anyway... Build-a' soil, SoHum, KIS Organics (I use them) are fine choices!
I use the KIS Nutrient dry amendment pack, just add in, mix, and let cook for a couple weeks someplace warm, and it's good to go! Next to no inputs for auto's, I still use certain occasional supp's like Si, kelp, humic-fulvic, micronutes (EJ Microblast), maybe some light PK boosting, and very impotantly, inoculant and enzymes! The soil herd is KEY in organics, they are what coverts and cycles the nutrients into forms the plants can absorb... These basic chemical forms are the SAME as what synthetics bring, plants to not distinguish between, say, nitrate from mineral salts or organic sources...Organics are slower because of this, but not by that much and you have no salt buildup issues to sweat over...
As for environment, in a word-- warm! Auto's
hate cold and will let you know it,... In organics, it's a bog down as well, so keep your girls warm even at night, above 65-70 if you can... upper 70's - low 80's day T's is the sweet spot....
RH% is really important too, and depending on where you live/grow, a snap or a bitch to deal with... RH% and T's are deeply tied together (look in Reference section about VPD, like Bill mentioned)... These affect transpiration rates, and thus how much and well water + nutes get hauled up from roots to tips!
nice gentle, even air movement is your friend, not blasting fans or dead air....
Anyway, that's an eyeful for now
