Quote Originally Posted by mbar
Dave, I was wondering if you think it would be a good idea to use flock after a stain treatment, when the stain is all off and there is enough sequestering agent in the water. I was thinking that if you use flock, then shut down the pump overnight, then vacuum to waste, it would then get rid of some of the metal that was in the water - or is the metal that combined with the sequestering agent just going to stay suspended in the water? I really don't know about real chemistry, so please excuse me if this is a silly question!
No question is silly if you don't know the answer! Not asking it is silly!
Floc works on particulate matter suspended (NOT dissolved) in the water which makes it cloudy. If the particles are too small for the filter they will continue to stay in the water. Floc will cause the smaller colloidial particles to clump together into larger particles that the filter will then catch. IMHO floc would be most useful with a sand filter which can filter to about 60 microns and less so with both cartridge and DE filters which can filter much smaller particles (this is just my opinion folks...we can agree to disagree!)
Floc would have absolutely no effect on chelated metals in the water
(they are dissolved in solution) unless the metals were starting to precipitate out(coming out of solution as particles) which is what happens when they show up as stain (they come out of solution and deposit on the surface of the pool).