If you're looking for samples check out Peruvian Gold if you're ever wanting to check out "organic". Wound up being one of my favorite "organic" products and they sent me a sample of their whole line. GH sent me a few samples of their cocotek (which happened to be right about an all-in-one product) when I was switching from "organic" nutrients.. And I end with MegaCrop. I have been using them for a little over a month and it is a true all in one. They offer a just pay shipping sample. MegaCrop is the real deal, most complete nutrient I have ever used.
I started with AN then went with "organic" nutrients for around a year before I started trying different nutrient lines with different plants.. I wrote to a couple handfuls of companies explaining what I was doing and a few responded with samples. Out of them, GH cocotek, was one of the cheapest but was every bit as good as the others (AN connoisseur, canna a cpl others) so I bought a couple of those big 2.5 jugs and stuck with that for a few runs.
Then I got the itch to try powders and tried Jacks and maxigrow/bloom which worked fine and I wanted to like them but I just wasn't getting as good of results as I was with the cocotek. I contacted Jacks about a simple feeding question and didn't say anything cannabis related but you could tell they werent interested in being associated with our community AT ALL...
I was getting ready to reorder some more cocotek a cpl months back when I decided to see what was going on in the world of nutrients. I was getting ready to pull the trigger on a different all-in-one (I cant remember the name offhand but the website had the word research in it.. it was another powder that wasnt quite an all in one because there were a cpl additives... i wanna say life+ or some shit.. anyways i digress) when i stumbled upon MegaCrop. It seemed like another nutrient that was destined to be "too-good-2-b-true" but then I hopped on here and saw that there were a few "reputable" members here who have been getting great results. I was going to get the sample to check out but then I saw the website was offering a 50% off deal on the big bag and I didn't want to miss out. The shit actually works BETTER than I had thought they would and my plants are happier than they ever have been. I'm on week 4 from flip and i'm not having to do a quarter of the staking/supporting that I had 2 do with most of the other nutrients. All the stems are thicker and stronger than even when I was adding silica with the cocotek!
tldr; try checking out megacrop
@GreenleafNutrients and you wont be dissapointed. Sorry I dont have anything to add about vitalink but wish you the best! Good luck!