On Mar 22, 2009, at 5:40 PM, dlancer7676 at comcast.net wrote: > Not sure about a 400 gal. vat. For a Spridget tub you need a tank approximately 13'Lx6'Wx3'D. That is 234 cubic feet. There are 7.5 gallons in each cubic foot, so; 234 x 7.5 equals 1755 gallons...... Kevin V.