hydro flush

hey all how should i flush in a dwc. should i use just plain phed water or buy a solution. and how long should i flush for currently im on my 7th week of flower and it was expected to finish on the 8th. should i flush now or on the 8th?

I am always reading to flush for at least a couple days before harvest, some growers flush for a week or more. How are your trichomes? Amber, Cloudy, Clear?

flush two weeks before harvest

5-7 days in hydroponics is fine