Now that we brought this back to life....
You can fairly easily turn any floating food into sinking food by doing the following
Take a syringe, remove plunger, fill syring with required amount of food, with finger over the tip, fill about halfway with water. Insert plunger and turn syring upright, remove finger and expel air as you would for an injection. Finger on tip again, pull plunger back, thus creating a vacuum in the syringe, remove finger, expel air, repeat (2-3x) until the pellets sink.
Works on freeze dried krill as well.