The IRF822 is a poor choice for this project; Rds (on) is rather high even when Vgs=10v, and you won't get half of that. The threshold voltage spec is for when I'd (drain current) is only 250uA, which isn't enough to light even ONE of the LEDs. Basically, IRFxxx devices are specified for Vgs=10v, where IRLxxx are specified for Vgs=4.5v, so the latter are suitable for use with logic-level voltages. I find it very handy to have some N-channel logic level MOSFETs around that have Vdss ratings of 30v, 60v and 120v for various projects. The lower the Vgss, the lower the gate charge and so with all other things equal, the lower Vdss rated will turn on/off faster.