When and for how long should I flush before harvesting?

Depends on substrate. Soil 2 weeks, hydro 1 week. It is a controversial topic. If a plant is fed right it needs flush time. Much better results. Personally done the experiment myself. Good luck and happy growing 🌱

Hello Fattorello90 you need to flush 2 weeks before your harvest. It is a minimum some people flush it even 3 weeks but 2 weeks is good. Just use tap water to flush your plant or you can use florakleen or cannaflush to wash your soil then just water. Good luck .