Hi sorry what is humic? I’m 3 weeks into my first grow ( soil ) using the same soil as used in this thread. I’m trying to go without any liquid fertilisers for the whole grow, I have been doing research on natural fertilisers like coffee grounds and seaweed...
humics are "organic matter" mostly really small stuff that's ancient.
important components of
humus, the major
organic fraction of
soil,
peat, and
coal (and also a constituent of many upland
streams,
dystrophic lakes, and
ocean water)
humic substances were often viewed through a lens of
acid–base theory that described
humic acids, as
organic acids, and their
conjugate bases,
humates, as important components of
organic matter. Through this viewpoint humic acids were defined as organic substances extracted from
soil that coagulate (form small solid pieces)
when a strong-base extract is acidified, whereas
fulvic acids are organic acids that remain
soluble (stay dissolved) when a strong-base extract is acidified.
There's probably some cute formula I could give you if I was intelligent enough on this matter. It would probably look something like the following: A- + B+ <=>(A- +C+) (B+ + C-) The arrows indicating greater or equal too.
Essentially, what humics do, is provide some basic building blocks to the puzzle and also allow "buffering capacity"
Buffer capacity (β) is defined as the moles of an acid or base necessary to change the pH of a solution by 1, divided by the pH change and the volume of
buffer in liters; it is a unitless number. A
buffer resists changes in pH due to the addition of an acid or base though consumption of the
buffer.
.
The plants look really good BTW, I would keep adding a little potassium anyway you can.
What I usually do here is this: I use some monopotassium phosphate at this time, pH balanced with some potassium hydroxide.
Watch your runoff ph and adjust accordingly, don't go any extreme, try to keep it right around 6.5 Aqua might have some other advice, or perhaps some of the others, but that's what I would suggest. For what it's worth. (yellowing/browning leaf tips).
At this point, I'd hit them with a mild every now and again until there finished. How far are you away from harvest?