i get what your saying with the dry amendments. you make your own "super soil" type of thing, but not subcools recipe. can you amend soil less like you can amend regular soil or is it a waste of time? I've heard that adding benificials is pretty much a waste of time but if a guy could run soil less like it were fox farm it could be really helpful in saving a couple bucks in nutrient cost. also, do you have any cheapo tricks for the thread?
The thing is that what we mostly refer to as "soil" on here is really potting mix; it's soil-less mix with stuff like compost\humus or earthworm castings added to it to improve the CEC, add nutrients and activate it biologically so it behaves more like real soil. What it is mostly based upon though is stuff like sphagnum peat, coco coir, etc. What you describe is basically what I am doing; amending a soil-less mix to make it behave like soil.
I start with Sunshine Advanced Mix #4, which I like because it is screened so it has a good texture, already has some coco coir in it too (along with sphagnum) and has mycorrhiza already (I add more at transplants). What I do to it is add compost or earthworm castings, more coco coir and sometimes vermiculite (but NO extra perlite). I don't add perlite because the SAM#4 has plenty already, and perlite doesn't provide or hold onto nutrients- it is just there to keep to media aerated, which coir also does and vermiculite does while having CEC (ability to hold nutrients).
Then I add the dolomitic limestone, kelp, alfalfa and more or less fishbone meal depending on growth stage and suspected nutrient requirements. Only other thing I add is Azomite (any granite or rock dust should do). Even if I don't cook/cure the mix, it really works just fine and I can just water it for quite some time granted the container size is appropriate. I might use some blackstrap molasses, and again I foliar when I can either with supplements or an actively aerated compost tea (this is where I'll use small amounts of guano) in veg and early bloom.
Honestly, to me the Subcool super soil is over kill and more complicated to use. Rev's mix is the same deal. If you look at their ingredient lists, they use 2-3+ different amendments for the same purpose. Not to mention, if you're using beneficials especially mycorrhiza they don't like high nutrient levels. Mycorrhizal fungi perform best with lower levels of available phosphate.
One thing that most growers fail to understand is how nutrients/amendments are labeled. NPK is not a good measure of nutrient content for amendments/organic materials. Labeling is also governed by law. The way NPK (in the USA) describes nutrient content is like this:
Nitrogen is often listed as a 'Total' sub-divided either into soluble/insoluble factions. The soluble faction is further described as ammoniacal/nitrate factions. Cannabis prefers nitrates, but various soil microbes are involved in converting ammonia N into Nitrate N (if they are present in the media).
However, the great majority of the time phosphorous and potassium are merely listed as Soluble or Available phosphorous and Soluble/Available Potash. In order to actually be plant 'available' the nutrient must be in soluble form. P & K are also listed as the "oxide equivalents", a chemical form they are not even technically present as. As far as I know, there are also a couple different methods for the determining the soluble/available faction.
Long story short, the great majority of labels don't describe the 'Total' P & K contents. Kelp meal, for example: a typical NPK label is 1-0-2. The '2' represents the percent of potash as if it were in oxide form (which it is not). The 'elemental' measure, still limited to describing the soluble faction, would actually be 1.66%. In other words, that is the amount of elemental K which is theoretically plant available
immediately. The 'Total' amount of elemental K could actually be upwards of 7%... this insoluble faction can be potentially made soluble by soil microbes over time.
http://en.wikipedia.org/wiki/Labeling_of_fertilizer
theres got to be a cheapo alternative. i have a feeling Nullis will know the answer. i haven't seen him around because i just came back to the site, but he made a couple posts on a thread that have to do with ion exchange that lead me to believe that he knows his science. i believe he is the jedi master that will use the force to show me the way to cheaper calmag supplementation.
