Nutes and flushing in DWC

[Formernuke]

For DWC the tutorial says to flush for several days but doesn't specify what several is.

My available day for harvest is next Wednesday, scheduled nute changeout is this Thursday so.

How many days before harvest should I change out the reservoir to just ph water?

Should I do the nute change or just top off till the change over?

[Tersky]

I've found that in hydro you only need a few day to flush. By a few days i mean 3-5 days. That being said, i wouldnt see a problem with starting the flush at your next res change since it's going to be less than a week till you harvest

[Obi-Wan]

How long really depends on the color of your leaves, how light you want them, and when the trichomes are ready. If your leaves are still fairly dark green 7 days of water only will result in some fading color. Personally, I like to drop the nutrient EC a little every week starting 3-4 weeks before harvest so I get a little color fade, then I can plan a short 3 day flush when the trichomes hit their peek and I have time to harvest.

IMO...flush is a term better suited to soil and coco growers. They have a medium that absorbs nutrients and it literally needs to be flushed away, it’s a process that can take weeks. As DWC growers a full reservoir change to water only achieves that in an instant. I think DWC growers are better suited using the term “Leach”. I start leaching or forcing them to use the nutrients they have stored roughly 3 weeks before harvest and the water only period is just like a plane circling the airport before landing.

[Formernuke]

Tricomes are ready (all plastic looking), next Wednesday is the day because I have surgery this week and that is the only day I can do the harvest. Leaves are changing color already as the nutes have been going down.