Looking for a sanity check on some math. I'm trying to estimate a production rate for applying organic products (humates, seaweed, compost tea, etc) using a backpack sprayer. Assuming I have a 4-gal backpack sprayer, it sprays about 1/4-gal per minute and I'm expecting to apply 1-gal of tank mix per 1000 sq-ft: I'm guessing it takes about 5 minutes to measure product and fill the tank (mixing on-site from concentrate), and I think that I can cover ground enough that I'm limited by my sprayer output, not my walking speed - so call it 4 minutes per 1000 sq-ft to spray. So my math says that for a 5000 sq-ft area, I'll need 2 tank fills (10 min) and 20 minutes application time = 30 minutes total (plus time to cleanup, etc.) Thirty minutes sounds like a long time for a 5000 sq-ft area, but maybe not. I'm new to this as a business, and while I've applied plenty of product before, it's always been at home or volunteer maintenance at a church, so I've not bothered to track how long it takes. Thoughts or comments? It may be that I need to adjust my tank mix so that I'm applying less than 1 gal/1000 - that's just the guide I've usually used for my organic applications. Also, how unprofessional is it to mix onsite using the client's water? Should I bring my own water or pre-mix before arriving? Thanks.