NPK is a common acronym in gardening. It refers to three main elements that support plant growth and their percentage ratio to each other within a fertilizer mix. You'll see it on bags of organic fertilizers.

N - Nitrogen ~ Leaf development and stem growth.

P - Phosphorus ~ Root development as well as flower and seed production.

K - Potassium ~ General immune system/disease resistance.

NPK is often represented like this example: 10-4-2.

In this example, there is a larger quantity of nitrogen in the fertilizer, a mid-grade level of phosphorus, and a lower amount of potassium.

Or it may be different.

6-9-3 is the basic NPK of guano, an organic fertilizer that drives cave-explorers batty.

There are other elements present as well and they are listed on commercially available products but NPK are the most important.

The NPK of Starfish?

1.8/0.2/0.25

*** Don't kill starfish ***