FOUR Coomealla High School students will milk a great idea for all it's worth at a "Shark Tank-style" competition in Sydney.

Jess Doidge, Zali MacManara, Megan Collihole and Izzy Newton, all 13, are in the Lower Baaka Academy of STEM Excellence.

As a part of the program, the girls will participate in the Orbispace Initiative, pitching sustainable milk cartons.

STEM Project Officer Ellen Macdona...