Skimming when using DT's

Yes...and no. Live and dead phytoplankton make up a large % of skimmate. In that respect, yes, the skimmer will pull out DT's. Of course, what you're really asking is whether the DT's will be pulled out before the corals can feed.

Short answer is I don't know. However, I will say that I don't turn off my skimmer, and I seem to be doing OK with the DT's. It doesn't come screaming out of the water like some of the trace element supplements do. I would suppose that as long as your circulation is good, the DT's will mix into the water column and act just like all the other "natural" phyto in the water.