How to do a reef tank water change

[Gripenfelter]

This is my routine:

Clean glass.

Drain out 6% of water (weekly water changes) by siphoning out water from the BOTTOM of the tank (Ammonia and poo is heavier than water).

Rinse out and clean filter media in old saltwater.

Mix new saltwater, add prime. Let sit for 10-15 mins.

Slowly add new water to sump, not directly to the display tank. I killed my waving hand xenias by adding directly to the tank. Different PH and water temp I guess.