Ranged Attacks

[eChris]

Hi, I'm trying to make Mages shoot ranged shots that only travel for 3 blocks.

Currently I'm using this to shoot stuff:

on shoot:
    projectile is arrow:
        if shooter is holding a hoe:
            while ground state of projectile is false:
                play green spark at projectile
                wait 1 tick
                push projectile upwards at speed 0.04
on leftclick:
    if player is holding a hoe:
        if {mana.%uuid of player%} is greater than 5:
            show 50 green spark at the player
            make the player shoot an arrow at speed 1
            set {mana.%uuid of player%} to {mana.%uuid of player%} - 5
            loop players in radius 32 of player:
                play sound "ENTITY_ENDERDRAGON_SHOOT" to loop-player with volume 5 and pitch 10

How can I make it so that the projectile is invisible, and disappears after 3 blocks?