Hi there. For the most part, I was able to put together a clean mix, but I haven't used the soil in the way I intended yet. A few months ago I contracted Covid one day before I was due to transplant my current plants into their final "home" which was a 4x4 indoor bed using this soil. Well, the day comes around when I needed to move that massive pile of soil inside and I couldn't get out of bed. So, I ended up dumping some of it into the biggest pots I had available which were 3.5 gal air pots....I knew it was a mistake, and if I had coco on hand I would have just used that and gone with another Maxibloom grow. Anyway, you can predict what happened, amazing veg growth-some of the best I've ever seen, then problems developed during stretch due to the small pot size and I had to start feeding additional nutes. So it wasn't a good test of the soil I made, but I still have the bulk of it in my front yard wrapped up in a tarp lol.
Let me know if there is any particular soil amendment or nutrient you are interested in and I can tell you what I found regarding heavy metals. Pretty much any aspect of the soil we make can be problematic depending on the source. Even things like perlite had led in some of the brands. My goal was "no detectable level" in everything I bought and for the most part I was able to stick with that. It makes me sad when I think about regular "organic" grows where "organic" is the goal and people don't check for heavy metals in their products, because I promise you, the average organic grow will have vastly more heavy metal content than a simple grow using coco and Jacks (a common combination) for example. People are so worried about pesticides, herbicides, and "natural" sourcing, that they ignore the most dangerous and pervasive toxins in our environment-heavy metals.
I never did make a list because I noticed that some brands might be clean at one point, then metals started showing up later on, so really the best thing you can do is look up everything in the heavy metal database, look at the latest test reports, and if they aren't listed, go with another product. Rock dust, all types, and seaweed, especially dry extracts, or ground kelp, are two of the most heavily polluted products. Some liquid seaweed products are totally free of arsenic however, but I couldn't find a single rock dust that is. Rock phosphate and greensand as well. Companies like Jack's and General Hydro (maxibloom) are probably able to reduce the heavy metal content of their phosphates during the refining process.
I feel a bit bad about making this thread to begin with, because I know how I felt when I realized the expensive soil I had been using for years was producing weed that would most likely either fail a heavy metal test, or at least throw up numbers I'm not comfortable with. But for people just starting out, who have yet to invest in this hobby, they can reduce their exposure greatly if it's a concern. I will personally never get tested for heavy metals because I'm certain my bones are riddled with them like a sickly Wolverine, but I hate that the government permits ANY LEVEL of them in fertilizer, because over time even trace amounts build up in the soil until they become a problem, and then it's too late to do anything about it. There is already a strong causal link between certain bioaccumulating crops, like brassica family crops, and cadmium exposure to breast cancer.
Sorry for the long post!