
DIY Homemade Liquid Fertilizer Monitor
After seeing a in-furrow and 2X2 fertilizer monitor system at the Farm Progress Show ($10,000+), I built this DIY system with an Android tablet, an Arduino based control box, and Amazon $10 flowmeters for around $800.

GPA Graph on Tablet

Gang of meters

3D printed meter blocks
I've simplified the fertilizer monitor app to just a graph of gallons per acre by row.
I use two monitors on my planter, one for infurrow and the other for my 2X2X2.
The flowmeters hook inline with the fertilizer tube going to each row. 1/4" and 3/8" meters are available.
The electronics send the flow/acre to the Android app.
See the Order page for parts used.