@Waira @Mañ'O'Green and others:
@Dankerson @JP1 @Mara Cachafa @throxic @Lil Dab @420autoflower - recently had a
discussion re: buffering coco.
I didn't want to derail that conversation over there, but had some related questions regarding growing with peat if anyone can provide thoughts or input.
I use Pro-mix HP without additional amendments, mineral salt feed with every irrigation, and germinate directly in the pots. I typically start with a 'nursing solution' that is my veg feed at 50% strength. I try to saturate the pots a few days before planting a bean, but otherwise just drop it directly in the pot. I'm not looking to change much about that process.
1) How would you recommend / what do you do (if anything) to 'condition' peat before a grow?
Peat has the same or higher CEC than coco, but I've never seen or heard anything about needing to (pre)buffer at the start of a grow. You couldn't soak peat the same as coco, but does anyone flush / oversaturate / run-thru with feed beforehand to 'pre-load' the peat at all?
2) How would you expect the calcium / CEC / pH behavior to differ between peat and coco over the course of the grow?
Pro-mix and other peat blends normally come with perlite and limestone mixed in. IIR, I saw somewhere once on the Pro-mix website that recommend wetting a week before planting to allow the limestone (CaCO3) to begin dissolving / mineralizing for pH reasons. So, would peat blends be adding / making available more Ca during the grow vs. coco continuing to buffer out / make unavailable Ca from the feed as the grow progresses?
I'd say there's literally an apples-to-oranges comparison between peat and coco... Coco is far far more bitchy and high maintenance mainly due to it's peculiar CEC properties with Ca and Mg... dealing with the Ca balance (Mg to a lesser degree because Mg is a weaker charge cation at +1 vs. Ca2+; this translated into stronger binding properties and all that entails).
Also, bad batches and poor quality brands can bring seriously PITA K+ and Na+ into the gig as they are naturally high in unbuffered coco.
there's lots of info on coco out there, so if you want details, wade into the research pool -
BTW, "buffering" in coco refers to CEC buffering, not just pH....
Since you're a ProMix grower, this is all moot... You need do nothing to this RTU soilless media; peat is an entirely different animal...
Both are devoid of any significant nutrient content, by design... So yeah, for seedlings it's common for folks to dose the media with a weak nute soln. beforehand. You'd be well advised to include humic-fulvic regularly as well for a variety of benefits (good article in Reference section at the Infirmary)...
As for part2 of your question, again research coco deeper if you want a proper comparison. This is a 2-page answer in my opinion-
In peat/soiless and true soil, the Ca source lime will deplete over time usually, but a big part of that is your pH along the way, your water hardness, and what nute inputs are going in...
By choosing soilless, you automatically assign yourself the
constant task of monitoring your incoming and out going pH and TDS/EC. it's the only way to keep tabs on what's going in in-pot! And that's the trick: in-pot does not = incoming soln. pH/ppm...
It'd be wise to cough up the bucks for a quality pH probe made specifically for in-pot readings (Blue Labs), these days anything else is unreliable crap IME......regular pH units are made for solutions only...
And all bulb-electrode type pH units require proper cleaning, storage (solution; NEVER use RO/DI water) and calibrations... flake on that at your our peril
.... ditto for EC/TDS meters too, but not nearly as often unless abused by not rinsing them after use in very low ppm water...