Hi Blade, its important to flush because you want all the fertilizer to be washed out. Nutes in your plant will make your grass taste harsh. So about 2 weeks before you harvest let water run through the soil and don't nute any more. Stachihttp://forum.grasscity.com/indoor-grow-journals/716779-stealth-diesel-ryder-autofem-grow.html http://forum.grasscity.com/outdoor-grow-journals/728732-2010-outside-monster-grow.html