want a varried diet but don't know what to feed

[gi4get]

we just bought two dwarf honey gouramis, a young red tailed shark, and a pair of otos. they are all very healthy and active but now we have a bit of a problem; what is the staple food in their diets? i know they like green veggies but we need something else when we can't get fresh foods. we also want a variety in their diets but can't find any information about it. we have been told gouramis eat pretty much anything (not very helpful), red tails love cucumber and sinking pellets (but don't know what kind), and otos like flakes (even though they seem totally uninterested). can anyone shed some light?

 

[The_Budmaster]

our Oto's dont really seem to eat much apart from bits of algae on the glass & on leaves, one of them has had a bit of a munch on some cucumber a couple of times & once it got to a piece of algae wafer before the barbs found it