I am looking into the possibility of having a tank for hauling around my herbicide mixes on my truck. I dont want to do the hose and pump system if possible because I simply do not have that many jobs. I think I can handle backpack spot spraying twice during the summer with only a few small accounts (after a granular trimec/fert combo application in early May) One question is how long could momentum be in a tank before the salts will settle out. No pump parts or the capability to agitate the mix or anything just a valve to open up and fill my backpack sprayers. Will the herbicide be mixed effectively for a week or two, or do I need to only mix up what I plan on spraying out that day? My guess is with my 10-20 lawn accounts I would need no more than a 50 gallon tank for the mix. The other question is where do I find small tanks like this? I just simply do not need a 200 - 300 gallon or more tank like I see on most lawn service trucks?