How much water do I use for flushing?

Hey guys,

I am about to start flushing my plants and I was wondering how much water do I have to use for my 10lt and 6lt airpots? I ve been watering every other day with 3.5 lts and 2.5 lts when feeding with nutes..
Are you flushing to remedy a problem in your growing medium?
Or are you talking about a pre harvest flush?

Before harvest usually you don't actually flood the medium to rinse it out. You simply water with only plain water for the last week or two. Unless you have a massive build up of nutrient salts that should be adequate
If you are talking about preharvest flush, just feed it phd water and let it finish itself off by using the rest of the nutrients in your medium. It will fade out nicely, and die off. The key is flushing at the right time tho.