Hello Carina --
Your fish need bloodworm, tubifex, earthworms and the like. Pellet/flake foods are of no use whatsover with these fish, so put them in the trash or use them with some other aquarium. Elephantnoses commonly starve to death in aquaria because they will only take live or frozen invertebrate foods. They are slow feeders and have small mouths. A spiny eel is thus a rather good choice for a tankmate, being another slow feeder.
Assuming you have two small (15-20 cm) specimens in your tank, they should be getting through about two frozen (not freeze-dried) bloodworm cubes per night, at least 5 nights a week. Any less is basically starving it to death.
Nice fish though. Good luck with them.
Neale
PS are you in Lincoln, UK, or Lincoln, NE?