I've been using drippers and micro sprinklers for many years on my container veggie garden, and now want to up my game. Fertilizing has always been the biggest problem, Plantone is great when planting but sucks to side dress after you've mulched. I've got a variety of emitters for different sized containers, from single heads, to drip hose with 6" spacing, to the sprinklers for whiskey barrels.

I bought a cheap 1/2" venturi injector on Ebay since it looked no different that the expensive ones and it's just a piece of molded plastic. After I set it up with the piping and diverter it seemed to work great, sucking up water from my test cup, till the system bled out its air and pressurized, and then it stopped sucking as the flow reduced. My flowmeter said I was flowing 1.3gpm at that point, and that sounds about right. I run 20 min and flow 25 gal. From what I read I thought a 1/2" unit should still be working at that flow. Could the rubber backflow valve in this unit be too tight? What if I just remove it and put the injector assembly higher than any other point in the system?

Any advice would be welcome.