I usually buy pretty large containers of fish food that last me a long time, but it has happened that I had none left. It was at this moment that I wondered what to feed fish when you don’t have any fish food.
During the first 2 or 3 days without fish food, aquarium fish will eat algae and scavenge for leftovers. After this there are several alternatives such as vegetables (lettuce, cucumber and zucchini) or meat (beef heart, cod or tilapia). Adjust the diet based on the type and size of the fish.
There are several ways you can buy time to head out and buy food or mix up their diet. However, you can’t just feed whatever “human” food you like. I’ll briefly cover what you need to know in order to properly feed your fish with temporary or alternative food.
Suitable (home-made) alternatives to fish food
Before we discuss when exactly you need to start feeding other food when you ran out, we’ll cover all the options that you have. Please take into account that different fish require different food; find out whether your fish are carnivores (only meat), herbivores (only plants) or omnivores (combination of both).
Suitable vegetables for omnivores and herbivores
Most community aquarium fish are either herbivores or omnivores, which means that vegetables are your best solution. Whether you’ve ran out of fish food or not, supplementing your fish’s diet with vegetables is always a good idea.
Suitable vegetables to feed to your fish include: Cucumber, zucchini, lettuce, spinach, peas (without out skin) or brussels sprouts
From experience I can tell you that your fish will probably not eat all these vegetables. When they’re used to eating dried food like flakes or pallets, they will not immediately recognize the vegetables as food. This will take some time and you’ll need patience.
Not all vegetables are immediately ready to put in your tank. It’s best that you briefly boil the vegetables to make them softer and make them sink. After you’ve boiled them you must first let them cool in some cold water before adding them to the tank. When feeding small fish, try cutting the vegetables in small “bite-sized” pieces. Don’t add it all at once because all uneaten vegetables will start to rot and pollute your water. The exception to this is cucumber which you do not have to boil, just stick a fork in it and add it to your tank.
Vegetables are great for shrimp, snails and bottom dwellers like bristlenose pleco’s.
What to feed meat-eating fish?
When dealing with fish that are used to eating meat you need to take a different approach. It’s also a little bit less complicated as you just add the meat to the tank and watch them eat it. Often it won’t take as long before the fish recognize is as food compared to feeding lettuce.
Suitable meet for fish consist of: beef heart, tilapia, shrimp, earthworms and other worms.
Popular examples of carnivorous fish are pufferfish, piranhas, arowana or other so called “monster” fish. It’s important to always feed the meat at room temperate. When you take the meat from a fridge, give it enough time to reach room temperature.
Whenever you’re dealing with omnivores you can also choose to feed meat. Many smaller aquarium fish are omnivores and love blood-worms, daphnia, black worms, brine-shrimp etc. It’s always a good idea to have some lying in your freezer, but if you don’t have any right now you can also choose to cut up some suitable meat to small pieces.
What to do if you do not have fish food for your aquarium fish?
Whenever you’ve run out of food or, like I’ve seen on some forum online, got home with a goldfish you won at a fair, you should not panic. Fish are resilient animals that can handle some time without food. When you’ve got a well established aquarium your fish can go without food for up to 3 days as there is algae, microfilm and leftover-food for them to feed on.
This means that you should not have to improvise with all kind of semi-suitable food as long as you can get some food for them the next day. All fish that can eat vegetables are made to digest plant matter and, when hungry, will turn towards eating algae.
Many well fed and pampered fish will never think about eating algae until them get hungry.
Also, if you can’t feed your fish for a day, do not compensate for it by giving it twice as much the day after. Instead, just give your regular daily amount. The reason for this is because most fish can’t handle all the food at once and will loose interest in it after a short while. All the rest will sink to the bottom and start to decompose, posing as a threat to the water quality of your tank.
Can aquarium fish eat bread? (No)
A lot of people want to feed bread when they have nothing else to feed their fish. Aquarium fish do not handle bread well because it will expand in their stomach. The expanded bread is a risk to the health of your fish as it could cause serious constipation.
I’ve written an article that answers this question in more depth. If you’re interested in some bread-like alternatives, definitely give it a read. You’ll find the article here on my website.
What human food can fish eat?
Next to all the safe and suitable solutions discussed at the start of this page, there’s hardly anything in our pantry suitable for fish. Any food that has been processed contains a wide variety of additives and mixes of substances that make it bad for fish.
The more processed it is, the less suitable for our fish. People have asked whether it’s alright to feed dog food to fish, and it most definitely is not. There is (among other things) way too much salt in all kinds of processed foods that are not suitable for fish.
There’s one thing that people feed to fish which is out of the ordinary: egg yolk. Boiled egg seems to be appropriate for fish, but you’ll need to be very careful not to pollute your aquarium water. I know I’ve said this 2 times before, but all food that’s left uneaten will cause ammonia in your water.
Fruit is another thing people can not agree about. I would never feed fruit to my fish because it contains so much sugar I do not believe it’s good for fish. Others say that a small piece of fruit on a weekly basis is good as it contributes to a varied diet.
Can fish eat rice?
According to an article on Fishkeeping Forever, fish will eat rice whether it’s cooked or uncooked. They’re talking specifically about goldfish, but I can image any fish that can fit rice in its mount will give it a go. Even when they’ll eat it, it still isn’t a good idea for the same reason you should not feed bread: it might expand.
Next to expanding it also does not provide any nutritional value to the fish’s diet next to carbs. It does not have any vitamins and is very starchy. In general I would refrain from feeding rice, but if you do make sure you boil it first.
Make home-made fish food
Finally I need to tell you about people creating their own fish food using “ordinary” food. The best example of this is from the King of DIY on Youtube. He has so many tanks that it’s just so much cheaper making your own fish food. I’m sure I’m going to try this one day and record a video for you, but for now I’ll let Joey take it away.