The real-life house used for the on-screen family home doesn't actually join directly to the garage, so the pool is visible from the front garden. A façade was added to make it appear as a single structure and to conceal the pool from view at the front of the property.
Wyatt Russell's father, Kurt Russell, was a highly accomplished minor-league baseball player and, were it not for an injury, would likely have gone on to play in Major League Baseball.
The school the children attend is called Harold Holt. Harold Holt was an Australian Prime Minister and a keen swimmer who went missing while swimming in the sea and is presumed to have died.
In 2018, director Rod Blackhurst and writer Bryce McGuire sold a feature-length adaptation of their 2014 short film Night Swim, about a woman terrorised in her pool by an evil spirit, to James Wan's Atomic Monster. McGuire is due to direct.
The entity that inhabits the pool is known as Temagami. It is an Indigenous term from the Algonquian language family, meaning 'deep water'. In Ontario, Canada, the name serves as a catch-all for a local municipality, the adjoining lake and river, and the First Nations community living in the area. This lends further verisimilitude to the film's internal mythology, which maintains that the pool's water comes from a natural spring that has existed for centuries.
All of the lore in the film stemmed from writer–director Bryce McGuire's imagination, though he drew broadly on established mythic traditions. The name Temagami may sound Japanese, yet it actually originates from an Ojibwa term used around the Great Lakes and, as Jodi Long's character explains in the film, roughly means deep water. Beyond that, however, the Ojibwa do not have a specific legend of healing waters; their most notable water-associated figure is Mishipeshu, a panther-like creature of the depths. McGuire chiefly borrowed the notion of wishing wells and curative springs — the familiar idea that tossing a coin into a well or fountain constitutes a small sacrifice that may win you a wish. In an interview with NBC Insider he says he examined various cultures that attach spiritual significance to water, including Celtic myths and the Sacred Cenote at Chichen Itza, and he also looked to the Bible, notably the reputed healing properties of the River Jordan. His aim was to probe the reciprocal relationship many cultures have with water, which led to the concept that the pool in Night Swim requires something in return for its favour.
