FLUSHING vs LEACHING?
'Leaching' a describes the even wherein liquids dissolve soluble minerals (in our case) as it passes through media.
'Flushing' is the process of dumping the water through the media.
Not interchangeable. But not a big deal.
FREE ONLINE DICTIONARY (I didn't edit out the part where your face gets red. Maybe it's informative.):
leach (lch)
v. leached, leach·ing, leach·es
v.tr.
1. To remove soluble or other constituents from by the action of a percolating liquid.
2. To empty; drain: "a world leached of pleasure, voided of meaning" (Marilynne Robinson).
v.intr.
To be dissolved or passed out by a percolating liquid.
n.
1. The act or process of leaching.
2. A porous, perforated, or sievelike vessel that holds material to be leached.
3. The substance through which a liquid is leached.
flush 1 (flsh)
v. flushed, flush·ing, flush·es
v.intr.
1. To turn red, as from fever, embarrassment, or strong emotion; blush.
2. To glow, especially with a reddish color: The sky flushed pink at dawn.
3. To flow suddenly and abundantly, as from containment; flood.
4. To be emptied or cleaned by a rapid flow of water, as a toilet.
v.tr.
1. To cause to redden or glow.
2. To excite or elate: The team was flushed with the success of victory.
3.
a. To clean, rinse, or empty with a rapid flow of a liquid, especially water: flush a toilet; flush a wound with iodine.
b. To remove or eliminate by or as if by flushing: "The weakness in demand and productivity will at least ... flush out some of the inflation premium that has been built into interest rates" (Fortune).
n.
1.
a. A flooding flow or rush, as of water.
b. The act of cleaning or rinsing by or as if by flushing.
2. A blush or glow: "here and there a flush of red on the lip of a little cloud" (Willa Cather).
3.
a. A reddening of the skin, as with fever, emotion, or exertion.
b. A brief sensation of heat over all or part of the body.
4. A rush of strong feeling: a flush of pride.
5. A state of freshness or vigor.