Minimum flushing...

Imho flushing should be done all at once. Spreading it out by watering for many days will overwater the plants and is unnecessary. You simply pour clean water through the soil until all solubles are washed away. Once that's accomplished and there aren't any more solubles in the soil, flushing more won't accomplish anything useful. Some people stick a hose in each pot for half an hour or so and some just slowly pour buckets of water through the soil.

The ideal time to flush is however long before harvest it'll take the soil to dry out again. You can let the soil dry out completely all the way through because you'll just be drying the plants afterward anyway. Because flushing waters the plants more than usual and also because they can dry out more than usual afterward, you flush around 50% longer than a normal watering cycle prior to harvest.

 

Not at all. I mean, not beyond what it normally absorbs each watering. Here's my write up on flushing:

There are two reasons for flushing at the end of flowering. The first is to end fertilizer intake, reducing the growth of new flowers and trichomes. Bud that first forms toward the end of flowering doesn't have time to mature and yields a speedier, underdeveloped, less potent and less enjoyable high.

The second reason for a final flush is to minimize the undesirable crap inside of the finished buds. Over the course of the flowering process, fertilizers and organic materials in the soil degrade. The longer the plant stays in a container and the more fertilizers it's given, the more crud will accumulate in the soil. This crap, along with microorganism waste, is taken in by the roots and transported throughout each plant. A plant can usually take care of toxins in its system over time, but if it's absorbing unhealthy substances as harvest approaches then that crap will still be in the buds when you smoke them. Even plain, fresh fertilizer with no old residues at all can easily affect the flavor and smoothness of the final smoke if the plant absorbs it just before harvest. Different types of fertilizers can affect the finished smoke differently, and organics commonly have less of a negative impact.

To flush soil, you simply run clean water through it until the runoff is clear with virtually nothing dissolved in it. At least three times the container's volume in water should be used to flush. Some substrates need as much as 5x the container's volume in flush water to fully rinse the soil.

Warm water flushes more efficiently than cold water. Since a building's cold water typically has fewer dissolved solids than it's hot water, growers should draw from the cold side and heat afterward to about 85 degrees F (30 C). It'll have lost a few degrees by the time it's applied. For best results, either the cold water should be carbon filtered or bottled water should be used, as always when growing. Neither heating nor filtering are necessary steps with flush water and aren't commonly performed. Small grows may take advantage of perfectly prepped flush water but it's not worth the trouble with large grows.

There are a few different opinions on when is the best time to perform the final flush. Mine is to make it the last watering before harvest. Because flushing soaks the soil more than normal, it will be longer than a normal watering cycle before the plants need water again. Add to this the fact that the plants are just going to be dried anyway, and the plants can go for at least 1.5x their normal watering cycle between flushing and harvesting. Ideally, the soil should be allowed to dry more than usual so that the plants are harvested a day or two after they would have normally needed a watering. Choose a date to flush with this in mind.

 

When I flush 2 weeks before harvest it just water on my regular watering schedule. I dont increase or decrease how much I give them its just straight water.

 

The point of a flush is to use ~3x as much water as normal

you're not just trying to saturate the soil as normal... you're trying to wash everything out. Using more water than normal doesn't matter, since you should have already been completely soaking the soil during waterings. The only effect of the extra water is to strip the soil of nutrients.

 

If your flushing close to harvest then yes that 3X would work. A 2 week flush with water accomplishes the same thing your just taking your time at it. Less hassle to deal with all at once especialy if your doing a bunch of plants.

 

I've always seen a 2 week flush recommended, not a 2 week "stop feeding and just water like normal"

everybody does it different tho

 

[quote name='"hello ladies"']I've always seen a 2 week flush recommended, not a 2 week "stop feeding and just water like normal"

everybody does it different tho[/quote]

Uh that's what a 2 week flush is

 

The trick is find what works good for you and go with it.

 

so "watering" and "flushing" are the same to you?

Like he said, whatever works...