Garden hose will cause some die off... But all the detrius & other toxins are gone.

Put in your sand and add all the salt water - make sure youve got live rock in the tank as there will be a slight amonia spike - live rock should handle it. Dont stir the sand for a few days, that way if theres die off/ ammonia in the bed its trapped... In a week once your confident theres no ammonia in the water, go ahead and stirr a small section - fingers in sand, just a section. How much depends on your tank size/live rock lbs/depth of the bed. Go slow and check you ammonia.

I did have bit of a spike and did a water change. I had live stock in there at the same time.

Using tank water will cause less die off in the sand but sand wont be as clean (unless you use a ton of salt water), other stored/saturated toxins my still be present.

Its a toss up whats better. Be prepaired for a water change and be measuring your ammonia.