Looking good Buds, could you remind me what 'MC calculations' means?
@InTheShed can explain this a lot better. I'm learning this through him & he has a way better understanding of it so hope he'll chime in & help explain it.
As simply as I can put it, the way we fed using MC was by reading the nitrogen need of the plant. As the lowers begin to yellow (showing an N deficiency), we would bump up the grams/gallon of MC. That worked great until we got to flower, at which point adding more N would raise the P, K, and Ca levels that often would show up as toxicities and deficiencies in other nutes that would get locked out.
So what a few folks here do is use the nitrogen ppm from the MC online feed calculator (at each g/gallon we would normally use) and make that our base N to build a better set of nute ratios from. Hence the term MC equivalent.
Those ratios vary slightly from person to person, but they are close to a 5-1-5 NPK, with Ca at 50% of K, Mg at 25% of K, and sulfur at 10% of N. In flower that changes to 5-1-6.
Other than the slight increase in K for flowering, the ratio stays the same from sprout to harvest, and the only thing that changes is increasing the ppm.
Finally, silica goes starts at 10ppm and ramps up quickly to 50ppm, and I keep it there all the way through stretch. After that I back it down to around 25ppm for the rest of the grow.