Hello Diverdown, the tabs I use are called Novotabs by JBL.
The Novo Tabs are specifically for Corydoras and they sink straight away but begin to disintegrate after a couple of minutes. The Cory's know when it's time for their tab - the Pandas are first in along with the Julii. There is a general free for all and they push it around the gravel like a hockey puck. As it rolls it crumbles and so some of the Cory's are distracted and pick up the bits. Once my Sterbae join in they just seem to nibble for a while and then chew on whatever they have broken off. They all get along very well. I tried breaking one into bits but it fell apart so quickly there was nothing left for them to nibble at and I was concerned that too much would settle into the gravel and be wasted. They should have no more than it takes to eat in an hour.
The tablet is usually gone in 45 minutes but they will spend all morning foraging for bits.
I also sometimes put in a Novo Fect, also by JBL, which is for the Otos but they don't seem too bothered.
The Rummies also like the tabs and once they start to break down the Rasbora hover around over the Corys feeding on broken off bits that float to the surface.
All round an excellent foodstuff, appreciated by all.
Here's a couple of shots: http://www.tropicalfishkeeping.com/m...ime-106842.jpg http://www.tropicalfishkeeping.com/m...imp-106834.jpg