Yes, those where from my tank but many years ago. I no longer have them.
The cover feeding is a good option when the "theives" are out. A better option to target feed in conjunction with the cover though might be some rigid plastic airline piping. Looks the same as the airline used for airstones except rigid. Using a hot kettle, you can manipulate one end to angle slightly so it can be targeted easily in front of each polyp. You can then attach a flexible air tube to extend the length and use a syringe like the large measuring one that comes with the Salifert kits to force the food out of the tube. As far as food size, it does need to be on the slightly larger size. Too smalll and it will not get enough nutrition. This is a zooplankton feeder, not a filter feeder.
Cheers
Steve