I watch a video in YouTube -link So this is your element based on your zodiac.

Waterbender = Cancer, Scorpio, and Pisces

Earthbender = Taurus, Virgo, and Capricon

Airbender = Gemini, Libra, and Aquarius

Firebender = Aries, Leo, and Saggitarius

If あなた didn't know your zodiac, check your 日付 of born below :-

Aries : March 21 - April 19
Taurus : April 20 - May 20
Gemini : May 21- June 20
Cancer : June 21- July 22
Leo : July 23 - August 22
Virgo : August 23 - September 22
Scorpio : October 23 - November 21
Sagittarius : November 22 - December 21
Capricorn :December 22 - January 19
Aquarius : January 20 - February 18
Pisces : February 19 - March 20