If the question relates to gallons of water, then in the UK I gallon = 10 lbs. In the USA 1 gallon = 8.35 lbs approx.
In the UK 390lbs is the weight of 390/10 = 39 gallons of water.
In the USA 390lbs is the weight of 390/8.35 = 46.71 (approx) gallons of water.
450 pounds of water is 53.892 US gallons.
1 cup is 8 oz . - So 450 lbs is 900 cups
390 US gallons = 1,476.31 liters. 390 Imperial gallons = 1,772.98 liters.
390 liters = about 103 US gallons.
390 mL per minute is about 148.36 US gallons per day.
176.901024 kg
390g is 0.86 (0.859803) pounds.
42 gallons of water is 350.7 pounds
390
10 US gallons is approximately 83.5 pounds
30 pounds of water is 3.593 gallons.
About 250.5 pounds for 30 US gallons.
10 gallons of water is 83.5 pounds
1437.4 acre feet.