When Marcia is practicing yoga in the den, we get a rare view of the ceiling above Mike and Carol's heads.
Most students enter high school as freshmen at the age of fourteen. However, Maureen McCormick was born August 5, 1956, making the actress sixteen years old when this aired in 1972.
Mike's hair is straight in this episode and was curly in the Hawaii episodes. This is because this episode was actually filmed before the Hawaii episodes yet broadcast afterward. This explains the continuity issue with the next episode where Mike's hair is curly until the end of the series.
Marcia is extremely tan in this episode.
Marcia mentions The Creature from the Black Lagoon, a classic horror film directed by Jack Arnold, who didn't direct this episode but had directed the most amount of total Brady Bunch episodes.