If you would like to know how many gallons do you need for 1 day, you can calculate this using the following steps:
2550 gallons ... 30 days
x gallons = ? ... 1 day
2550 * 1 = 30 * x
2550 = 30 * x /30
x = 2550/30
x = 85 gallons
The correct result would be 85 gallons.