View attachment 4071032 I would recommend General Hydroponics Flora line. You definitely don't need to flush for a week.. I would empty current water and put in fresh clean water for an hour then empty again and replace with nutrients made for hydro. I've been DWC for years and have used different brands with great results... if you need help...it's here.
I placed an order for Mega Crop nutrients earlier this week, Starting a new grow with it to see how it do. I like the fact that it's an all in one nute and pretty inexpensive.