Siphonex help needed

[fotofashion]

I recently bought a siphonex and am happy I did except for one small problem that I know you who use this device can help me with.
What type of nozzle or control to turn on and shut off the mixed water/fertilizer do you use. My difficulty seems to be "back pressure" with the controls I have tried to use. Because of the back pressure the dilution rate does not work. I tried to use my water wand (which I would prefer to use) but that does not work. I bought an inexpensive nozzle that is used for just watering and that did not work either. I also tried using just one of those shutoffs and I am not sure how well it worked either. I kind of get the idea that whatever control I use has to be turned on full blast so that seems to eliminate the nozzle.
Ideas and suggestions from those who have experience please.
Thanks
Beverly A.