Sometimes, it isn't the cost whether it is cheap or not. When nutrition marketer put label under "Cannabis", they put high markup for the same nutrition that you can use for your regular vegetable garden. This homemade calcium from the eggshell is great way to make calcium supplement for cannabis or any of the plants.
KNF (Korean Natural Farming) is all about using natural nutrition to grow things and there are several different nutritions you can make at home - all organic. And once you made the nutrition, it can be added to water 1:500 ratio.
If anyone interested in KNF, there is very good information on YouTube by
Chris Trump. He learned this method from KNF master.
Here is more about
KNF
It is now spreading through Cannabis growers. YouTube has KNF on the cannabis seminar series.
I made a few KNF nutritions. It's very gentle food for the plants.
LAB (LActobacillus) from rice water + milk --helps increase the ability to absorb nutrients
WCA (Water-soluble Calcium) from eggshell and rice vinegar
FPJ (Fermented Plant Juice) - Vegetables + Brown Sugar --Natural form of nitrogen
FFP (fermented Fruit Juice) - Fruit + Brown Sugar --Phosphorous: Giving during Flowering Period
FAA (Fish Amino Acid) - Fish + Brown Sugar --help strengthen the plants' natural immune system, potentially reducing the need for pesticides and fungicides.
and many others that you can make at home. These are good nutrition and can be replacing typical bottled nutrition of CAL, NKP, and Molasses.
And most of these nutritions, it only takes few days to a week except FAA (takes min. 3 months- longer the better)