They really won't make use of the DT's, although the smell of it in the water must really whet their appetite.
Throw a piece of krill, shrimp, or mysis on that big boy and it'll almost seem to burp after it's done eating.
Paintbug, here's a way that may cause your canes to put out some feeder tentacles at night. If you have some flake food, crush it up in your fingers into a dust. Put your hand near the can and let the fine dust sort of settle onto it. I can almost assure you that you'll see 'em pucker up for ya.