Can I refil a paintball tank with air

It's possible, but not recommended. Most paintball places are using HPA (high pressure air) now anyway. You can purchase a new 3000psi HPA tank off of Amazon for about $40. The problem is that they're all regulated to about 800psi for paintball guns. You can modify the regulator to allow it to fill up to 3000psi though by adding or re-arranging the belville washers to make the opening larger.

http://smile.amazon.com/Empire-Basic-Alu-48ci-3000psi/dp/B0068I2E3E/ref=sr_1_1?ie=UTF8&qid=1447697688&sr=8-1&keywords=empire+3000psi

Being that it is only 3000psi, you may only get a single full fill of your gun with it, but the upside is that you can refill it with a manual pump.
 
"Bullwhisper"I'm looking to buy one of the pops from archers air guns .com or I might just get a disco still a toss up, long question short can I refill a co2 tank like what's on a paint ball gun with high pressure air?
You can, but you are limited to an 1800PSI fill. Your Co2 bottle should be stamped with the 1800 pressure right on it. A standard paintball regulator will screw right in place of the CO2 pin valve.
I've got one that I set for about 1000psi and I can shoot my 2250XT from 1800 down to 1000 and get just about 75 "regulated" shots just a little over 12FPE. (12.4 actually)