Cost of nutrients

 This is something I've been wanting to do for a while- figure out how long nutrients that I have purchased will last me, and what my unit cost is. I just decided to start purchasing my nutrients in bulk. Including sales tax, a 16 pound container of Maxi-Gro costs me $95.

This means that I'm getting a unit price of about six dollars per pound. Next I need to compute how many batches of nutrient solution I am getting per pound.

Measuring by hand, I have determined that there are 20 tablespoons of Maxi-Gro powder in each pound, so the volume breaks down like this:

1 pound = 20 tablespoons = 60 teaspoons

for the entire container:

16 pounds = 320 tablespoons = 960 teaspoons

This makes the cost of each teaspoon of Maxi-Gro almost exactly 10 cents.

Peppers and tomatoes, which are heavy feeders, receive nutrient solution at a concentration of 1 1/4 teaspoons per gallon of water. I use four-gallon reservoirs, so this means that each time I change out the water in a plants' reservoir, I use five teaspoons of Maxi-Gro powder, for a cost of 50 cents.

I change reservoirs weekly, so the total cost of fertilizer is 50 cents per week per plant.

Now our breakdown of volume looks like:

16 pounds = 320 tablespoons = 960 teaspoons =  192 five-teaspoon doses @ 50 cents each

This is enough nutrient to feed one plant continuously for 3 1/2 years, or a year's supply for four plants.

I assume that the volume measurements are similar enough that the same applies for Maxi-Bloom.