I dose 16 Oz every other day. I have a 200 gallon tank, with a large Maxima clam, a ton of Euphyllia, and a few SPS. Also 19 fish, from Tangs, Angels, Wrasses etc. I have been dosing this amount for years without adverse affects on water quality, etc.
200 microns....technically a coffee filter would work as well. I don't use filter socks in my sump, so I had these old ones laying around so I used them.