Finally!

So here's a shot of the 1" venturi I use, but any size is doable with PVC pipe. 2" attached to a 1" section that has a tee and a cutoff vale, and back to a 2"pipe is all it would take to use it on your system. I don't believe a straight 2" tube would have enough pressure to pull chems from a tank.



This is my system. The 1" Chinese pump is the only moving part, and chemicals never touch the pump. I've used that pump for going on 8 years, and never had a burp. The inlet hose pulls water from the pond, and I carry a 10 gallon chem tank for whatever herbicide I'm using. With venturi systems, viscosity is important so even if I only add 2-3 gallons of chemicals, I'll fill the rest of the tank with water. I add a bilge pump the the chem tank to keep everything evenly mixed.



My primary rig is a 3 drop 8' boom, and it's pulled up for storing in this pic. I float, or weight the chem hoses depending on what I'm targeting. A gun would be usable too, but to be honest, I fish while I spray. Grid patterns work best for me. I hope this helps a little.