I have a rain barrel 20 feet below a deck. I want to pump water from the rain barrel up to a small container (2 gallons) once a day. I'm thinking it should take less than 15 minutes to fill. I've found a pump I like that has the following specs, but it may be too powerful, but it's cheap ($15) Head Pressure 80 psi ( I think this converts to about 180 feet for water?) Flow rate 6 LPM. (I assume that this is the flow rate with 0 head pressure through it's 1/2" port?) How do I use the 6 LPM to calculate the flow rate through say a 1/2" hose? I don't want it dribbling out and taking an hour to fill, but I also don't want it splashing out with force.