Deciding on what to feed a fish when out of fish food depends on what is readily available or easily prepared beforehand. What you can feed fish other than fish food is determined by the kind of fish.
After catching worms and maggots in your trap, simply clean them with running water to remove debris. The water used to clean the worms and maggot can also be used to water your plants and soil.
How To Prepare Worms and Insects As Substitute For Fish Food
Duckweed, Azolla, and Algae Are Suitable Substitutes For Fish Food With Good Protein Content
Some plants provide good protein content like algae, azola, and duckweed. These aquatic plants grow naturally and you could feed them to omnivorous or herbivorous fishes like Tilapia and Koi.
Growing Algae In A Separate Container Is Advisable Before Preparing Them For Fish To Eat To Prevent Algal Growth In The System
Algae come in two major types; macroalgae and microalgae. Macroalgae include kelp and different types of seaweed. Common microalgae that are commonly available are spirulina and chlorella used for food and nutritional supplements.
Catfish and Pangasius Are Essentially Bottomfeeders That Essentially Eat Anything Even Chicken Manure
Catfish and fishes from the genus pangasius eat anything, even each other. These are bottom feeders that will survive even without eating for prolonged periods of time.