I saw a comment about backpack spayers in another thread and wanted to start a post about them. I agree that BP sprayers can and will leak...and i have been the recipient of a pretty nasty SH burn due to this!. There is one backpack sprayer I will use. It's a totally "top-pull" sprayer, meaning the fluid is pulled from the top and the resevior is totally sealed on the sides and bottom. You can find them at harbor freight tools. This week they are on sale for 19.99. Warning, they are not meant to last. I've not had a mechanicsm in one work for more than 2 months. Which is about the same time my pump up spayers last. I'll try and post a picture later.