Alex V. '18 Wins Second Place in Engineering Research Category at LA County Science Fair

Alex designed a natural filtration system that would effectively maintain safe water chemistry levels for marine fish.

In 9th grade, Alex V. ‘18 became interested in doing her own science research outside the classroom. Working with Marlborough Science Instructor Jay Buckley, she explored ideas around fish tank filtration, resulting in a two-year research project designing a natural filtration system that would effectively maintain safe water chemistry levels for marine fish.

Most current filters utilize chemicals and are made with pounds of plastic and inorganic materials. And once a filter is thrown away, it takes years to decompose, often making its way to the oceans and harming marine life.

Instead, Alex’s filtration system uses a two-tank system. One tank is used to house up to a dozen reef fish with sand substrate, and the other tank serves to house the organic filter materials, including rocks, sand, mud, gravel, and mangrove plants. Water enters the filter tank, moves through the organic filtering materials, and then moves to the fish tank through a tube. 

Over the course of four months, Alex maintained consistent pH, salinity, and temperature levels. Each week, she took measurements of the ammonia, nitrite, and nitrate levels. After 30 days, she saw the levels of ammonia decrease from 0.25 ppm to 0.0 ppm, nitrate levels similarly moved from 60.00 ppm down to 5.00 ppm, and nitrite levels moved down from 5.00 ppm to 0.00 ppm. 

From this data, combined with the fact that all fish remained healthy, Alex concluded that the organic filter is a viable alternative to a commercial filter with possible implications for creating a natural filtration system for fish farms.

Presenting her project, “Can a Natural Filter Maintain Stable and Safe Water Chemistry Levels for a Salt Water Filter?”, at the LA County Science Fair was a new experience for Alex. 

“It was very intimidating to be around people who had been doing science fairs since 5th grade and many other very interesting projects. The judges were all very friendly, and after the first 30 minutes it became much easier,” said Alex. “Overall it was a fun learning experience.”

Winning second place in the Engineering Research category, Alex qualified for the California State Science Fair, which includes 900 projects competing for awards totalling $60,000 and a chance to move on to the Intel ISEF Fair. 

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