Best use for this technique is actually if you have problems with greedy surface and mid water eaters, eating pellets before they reach the bottom eaters.
Just stick the pipe in and send the food down to the bottom then use the pipe to hide the food in the gravel, with a little shuffle. The bottom eaters will soon snuffle around and find the hidden food but the surface and mid eaters won't.
Thanks, I tried this method out, I got a peice of clear pipe about 5 inches thick and got the Betta Inside it, Then I put some food into the end, Although the other fish (Dwarf Gouramis, Platys and Danios) had been fed an hour before, they still tried to eat the Betta's food.
Now the Betta seems to be happier and is swimming around the tank with all his mates....