Honors College Theses

Comparing Water Quality for Aquaponics Systems with Different Solids Removal Methods and Biofilter Media, and Effluent Output to Grow Beds

Publication Date



Biology (B.A.)

Document Type and Release Option

Thesis (open access)

Faculty Mentor

Heather Joesting


Aquaponics is a closed-loop, sustainable method of food production that combines fish and plant production. This method of agriculture has the potential to bring fresh, local food to food-insecure areas, but challenges remain due to high operating costs. In order to develop a strong aquaponics industry, the creation of the most efficient system designs will be critical in optimizing production. This study’s purpose was to compare water quality between two aquaponics system designs that differ in filtration and solid removal methods. System 1 used a sock filter for solid removal and Kaldnes media for biofiltration while System 2 used a backwash settling chamber for solid removal and biobeads for biofiltration. To compare water quality between systems, water samples were taken from seven locations throughout both systems and analyzed for ammonium, nitrate, potassium, pH, dissolved oxygen, and conductivity weekly from August 2019 to December 2019. Results showed significantly less ammonium, nitrate, potassium, and conductivity and significantly greater dissolved oxygen and pH in System 1 compared to System 2. These findings suggest that System 1 is more efficient in both converting ammonium to nitrate and solid removal and potentially created more optimal conditions for plant absorption of nutrients and fish growth. This is likely due to the combination of an overall higher flow rate that led to higher concentrations of dissolved oxygen, allowing for the higher nitrification rates, and the more efficient biofilter media (Kaldnes media) and solid removal method (sock filter) of System 1.

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