Member of the Month: May 2009, Oct 2010, Sept 2017
Just about anything that's relatively inexpensive, lol. Make a list of all the nutrient brands you can think of that have ever been used to grow cannabis. Now switch to the grow journals section, then the "completed" sub-forum, and search the completed grow journal threads for the brand (remember to select the option to search only that section of the forum). You'll probably find successful grows on which the brand was used.
If you just want to add one (nutrient) item to your virtual shopping cart, enter your billing/shipping information, and wait for a convenient nutrient kit to arrive, you can do a web-search for:
Techniflora Recipe for Success Starter Kit
...then read all the information and decide whether you can afford it. It's a good brand, can be had for around $50 (occasionally a little cheaper) delivered to your door, has simple instructions, is a multi-part nutrient - so you can get used to making a nutrient solution from separate components and tailoring the mix to some extent as the plant's needs change - and has been used to successfully grow cannabis for decades. There should be enough in the kit for a small grow as long as you don't waste it. Generally speaking, with plant nutrients, a little goes a long way, so it's better to go easy on them; if you start off using less than the manufacturer recommends, you can always add more if the plant shows signs of being deficient.
I'm not trying to imply that the above is "the best," because who knows what the best is - but it's pretty good. And the kit doesn't scream "sure, this will work, but you really should also buy..." if you know what I mean.
There are several (lots of?) other nutrient kits on the market, so if you don't like what you read about the above, a web-search engine will show you other choices. Or you can assemble your own "kit" from individual components. For that matter, if you're lazy and/or poor, you can spend a few bucks on a little bottle of Osmocote Plus time release dry nutrients, and grow decent cannabis.
Get a decent digital pH meter (along with the proper calibration and storage solutions), an EC (electrical conductivity, aka "TDS" and "PPM") meter if you can afford to, and read one or more of the illustrated nutrient deficiency/toxicity threads if you have not already done so. These things will help both you and your plants greatly.
General Hydroponics nutrient trio. Not expensive, easy to use, and has been growing awesome plants for a long, long time. Those 3 bottles are all you need, with very little exception. Maybe some cal-mag, depending on water, and then maybe some Z7 or hydroguard if running a hydro setup to keep the res in good shape.
Start there, and keep it simple. Ignore all the fancy advertising bottles, resist the urge to "know better than the bottle", and stay the course.
Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016 - Photo of the Month: Nov 2020
I’ve used all those kinds to some extent, including soil. I’ve been impressed with the gaia green stuff in the greenhouse, veggie and herb garden. The Remo lineup has a few too many bottles for my liking. You shouldn’t need more than three IMO, four tops. GH trio is a basic simple line- not perfect but gets the job done. Owned by Monsanto’s evil cronies- major points off for that.
Soil and gaia green would probably be my top two choices, but it depends on your individual needs.
Just avoid getting sucked into nutrient lineups that imply you need a dozen bottles. That’s just a scam.