The aim of project VG13052 was to confirm the practical and economic feasibility of ultra-filtration as a technology for nutrient solution disinfection. This information is highly relevant and valuable to all hydroponic vegetable growers in Australia.

The capture and reuse of nutrient solution run‐off not only improves water and fertiliser efficiency and therefore improved profitability, but consequently has significant environmental benefits too. A pathogen free source of water is critical to efficient and cost effective greenhouse and hydroponic production as well as the reuse of run‐off water, which makes investment in reliable water disinfection essential. There are a number of disinfection technologies, yet high costs, inconsistent results and the use of chemicals are obstacles to widespread industry adoption of improved practices.

Key activities and corresponding outputs of this project have included a technical presentation at the peak national industry conference and an explanatory article in leading industry media. Extensive efficacy research trials have been completed as a key component of the methodology used in this project and this research has determined that while ultrafiltration currently offers a good option for removal of fungal pathogens, it currently does not provide adequate retention of key bacterial pathogens. Project activities have also included research into the detection levels of target pathogens in water and confirmation that the nutrient profile in hydroponic solutions is not adversely impacted by ultrafiltration.

This project has been able to evaluate and demonstrate the opportunities for closed system hydroponics and increased run‐off targets and clearly shows the merit of investment in water disinfection. Overall, the economic viability of closed system hydroponics with disinfection is confirmed.