Marine Mix is made from prawn, fish and squid and blended up before being frozen into small cubes. It makes a good food for most fish but you might need to cut it up finer with a pair of scissors depending on the brand.
Marine Green is the same as marine mix but with spinach or algae added to it.
Bloodworms might be a bit big for Khuli loaches.
Frozen brineshrimp (especially the baby brineshrimp) would be small enough, or use a pr of scissors to cut the adult brineshrimp up.
Micro and grindal worms are good and can be cultured at home quite easily once you get a starter culture.
The following link has some info on culturing micro worms. It's about 2/3 down the page.
Grindal worms can be cultured in peat moss or potting mix and fed on dry baby cereal.