I have a concrete slab which can fit a hot tub approximately at a distance of 8 feet from the main breaker panel (located outside on my porch). I assume that I will still need a separate disconnect for the hot tub (minimum of 5 ft from the tub). Can I just pop the disconnect box (with GFCI breaker and 120V outlet) directly next to the main breaker box and then run my #6 cables from there to the hot tub (~20 ft total)? Or does the disconnect need to be separated from the main for some reason? Thanks!