Quote Originally Posted by Fman View Post
First off, nice chart.... well done.

I am surprised the Tsunami 800 is only putting out 7.5 GPM, they are rated by Atwood for around 14 GPM. I know I am getting better then 7.5 GPM out of my 800's in my setup. With all three 800's running, drafting out of one 3/4" intake, I am getting about 9.5-10GPM per pump, close to 30GPM when running all of them. It takes me about 8-8.5 minutes to fill 1900 lbs of ballast which is about 228 gallons.

Could you possibly get a little more flow from the water pressure coming in from the bottom of the boat when they are mounted well below the draft line??????


Unless my calculations are wrong if you divide yout total weight by 8.35 you get 227.54 gallons then divide that by the three pumps (assuming all bags are equal weight) you get 75.84 gallons for each pump then divide that by your faster fill time of 8 minutes and you get 9.48 GPM per pump if you use the slower time you get 8.92 GPM. It is a true statement that if you spread the GPM across all three pumps your setup can do 28.44 GPM or 26.76GPM. So in your setup you are seeing slightly better results if the timing you have posted is accurate. Could you verify your timings with a stopwatch or use the 5 gallon bucket method. I want to make sure that all timings were gatherd in a similar method.