RS-360H DC Water pump - How to supply it ?

I'll keep it simple, I have a small DC water pump RS-360SH and I am having a lot of trouble finding a good way to make it work.

I want to use a AC adapter to power it up via a relay module for arduino to avoid using a larger, expensive PSU because I am on a budget.

Right now I can sort of make it work with a 9v 1 A adapter but still it isn't powerful enough for the pump to suck water, and I've even tried a 12V one at 1.5 Amps and the pump doesn't do anything it just like it wants to turn and gives up.

I have the Datasheet of the motor but It's not looking good, maybe I could reduce the voltage on the 12 v 1.5 Amp adapter to 9v or I don't know.

I'd appreciate any help!

The stall current is listed as 8.6 amperes at 7.2 V. Your power supply must be able to supply close to that current for proper startup.

8.3 Amperes for that little pump? Wow that's a lot, I assumed I would be good with 1.5 maybe 2 Amps at 9 volts.
The pump won't work too hard because the reservoir would be very close to the pump maybe a couple of inches above it and the water won't have to travel very further or with a lot of pressure (I am building a small greenhouse).

Thank you for your reply but It's not looking good for the project, the last thing I want to do is to buy a huge power supply for such little pump, it wouldn't look that great.

The pump will run on lower voltage, at lower startup current.
Look in thrift shops for used power bricks. It is pretty easy to find ones capable of 6-8 amperes.

I've got some good results with a 5v 2.5 Amp adapter I had laying around ! It probably didn't work last time because of a bad electrical connection but now it works great ! Thank you for your replies !