You can culture Daphnia in plastic tubs that are kept outside in a shady place. Fill a 60+litre container with freshwater and add 1 heaped tablespoon of lawn or garden fertiliser for each 20litres of water. Have an airstone bubbling away if possible. Leave the mixture for a few weeks until it goes green. Then add some live daphnia and wait a couple of weeks until there are heaps of them. When there are lots of them you can harvest them to feed to the fish.
If you live in a cold climate like Scotland you can keep the culture in the open so it gets more light. If you live in a hot climate keep it in the shade.
Cultures can be kept indoors under fluorescent lights but you need a lot of light. You can keep the lights on continuously if needed. Give the cultures enough light to keep the water green.
After a few weeks you should start a new culture and by the time the water goes green (in the new culture) the old culture will be running at full capacity and probably be starting to run out of food (green water/ algae). When the new culture is green you can add some daphnia from the first culture to inoculate it.
The red bloodworms (Chirominid midge larvae) live on the bottom of containers that have lots of rotting plant matter in them. If you add a couple of lettuces to a container of freshwater, and leave it to rot down, you will start to get a few bloodworms after a couple of months. Unfortunately you often get lots of mosquitoe larvae when the culture is first started and the water smells awful. Aerating the mixture will help prevent it stinking as badly.
Mozzie larvae are actually a better food for fish compared to bloodworms, and you get a lot more of them a lot easier and quicker than culturing bloodworms.
