DIY Preservative Applicator Help

I'm trying to build my own applicator for a JD 348 planning to us NH Crop Saver @ 4# per ton.  Everything is in place but I'm having problems getting the flow rate low enough.

 

What I've got so far:  A 25 gal Ag Spray tank with a 1.8 gpm Surflo pump.  The set up looks identical to the Crop Care unit.  I ordered the nozzles and tips from Crop Care.  I have a John Blue pump controller mounted in the cab with a 4" pressure guage mounted at the applicator tank.

 

The problem:  It applies way too much product with the smallest nozzles.  The pump controller only brings down the pressure to about 45 lbs.  ( I probably should have saved that $200 and bought some aspirin instead).

 

My next step is to buy a pressure regulator and mount it at the pump.  But, even at 15 psi there will be too much flow according to the TeeJet chart.  There goes my idea of adjusting pressure on the fly.

 

So, what nozzle tips are you guys using?  Any other suggestions?

DIY Preservative Applicator Help