Canister filter increase volume

Hi every one. I know every one says canister filters are not great and can lead to a build up in nitrates. I have a small nano tank holds 65 litres of water. I have a large new canister that holds 15 litres. Was given it. BCan I run it with no media ( empty) to increase water volume ( over 20%) and increased flow. This would not increase nitrates would it . And wouldn't have to be cleaned as often? Maybe even add small amount of live rock?? ThLights any one???? Good or bad idea