When I still had my greenhouse, I used a metering pump to feed fertilizer concentrate into my irrigation water. Now that I have a much smaller collection and use a pump-up sprayer to water my plants, I have found that using powdered fertilizer is a hassle. Fortunately, my packaging supplier carries self-measuring "Bettix" bottles.

A Bettix bottle has two chambers, a larger “holding tank” (to the left in the image above) and a smaller, graduated measuring or dispensing chamber on the right, connected to the holding tank by a molded-in tube going from the bottom of the larger chamber to the top of the smaller one. Operation is as follows:

  • Add fertilizer powder to the holding tank.
  • Add water to that tank and close both tops, shaking to dissolve the powder.
  • Loosen or remove the cap from the dispenser side and squeeze the holding tank until the dispenser is filled to the appropriate level.
  • Pour that concentrate into your fertilizer application jug, then replace the cap.

For example, I want to apply 100 ppm N using K-Lite to my plants weekly. From the label, I know that 100 ppm N requires 2.9g or 3/4 teaspoon of that fertilizer powder per gallon.

My Bettix bottle has a 67 ounce capacity – perfect to hold two quarts (64 ounces) of solution. I have decided to use 2 ounces of concentrate per gallon so that my concentrate doesn’t run into solubility issues, so I must add 2.9g to every 2 ounces of concentrate, or 2.9 x 32 = 92.8g (24 teaspoons) of powder to two quarts of water, giving me enough concentrate for 32 gallons of solution to be applied.

So now, I just have to shake the bottle, dispense the two ounces/gallon into my pump up sprayer, fill that with water and I’m good to go.