Need help with home made water tank

I work at a carwash and i'm starting my own mobile detail business. At the carwash we have 55 gallon drum tanks and i took one home to make my own portable watertank. i have made a hole at the bottom on the side of the watertank and put a water valve to open and close and to get water from the tank to a Honda 2600 psi pressure washer that sprays 2.5 gallons per minute. After doing all that i cant get the water to pressure washer from the water tank. Is there anything that i can do to amke it work cuz i don't have the money to buy a good water tank?

The reason the water is not getting to the water tank is that the water is flowing by gravity right now, you must add pressure to the water coming out from the tank.

(Water tank)open/close valve(plastic)---
-
-
(pump)
+
+
+
(pressure washer)

(-)=copper pipe reccomened
(+)=hose

P.S. You can find the valve, hoses, and pump at home depot. Get the larger pump its about $200.00, you will find it creates more flow of water to your pressure washer!

If I bought a mobile water tank would i still need a pump to get water to the powerwasher?

Some tanks you can buy that have a pressure system, but are very costly! I bought a 300 gallon waster tank for $350.00 (heavy duty/ without pump) pump $150.00 wish that i would have gotten a bigger one... copper pipe $15.00, hose $15.00.. I did all the install my self!

Also, if you have a problem with the pump it's easier to replace than if it is made into the unit!