Can Goldfish Eat Bloodworms? (Caution Advised)

Last Updated on 2023-05-24

When looking for alternatives to fish flakes for your goldfish, blood worms are bound to be recommended at some point. However, can goldfish eat blood worms, or do they do more harm than good?

In this article, you’re going to find out whether goldfish can eat blood worms, what’s good and bad about them, the different ways you can feed them to your goldfish, and some great alternatives!

So keep reading to find out whether blood worms are the best choice for your goldfish!

Can Goldfish Eat Bloodworms?

So can goldfish eat bloodworms? In moderation, bloodworms are a great treat for goldfish; however, they should definitely remain a treat and not be a staple of your goldfish’s diet. If you start feeding your goldfish bloodworms too often, it can cause a variety of problems. So like all things, moderation is key.

What Are The Benefits Of Bloodworms For Goldfish?

There are definitely some great benefits of feeding blood worms to your goldfish that shouldn’t be overlooked. Here are a few of the biggest benefits your goldfish will get from eating blood worms.

They’re High In Protein

Blood worms are extremely high in protein which makes them a great treat for your goldfish every once in a while. If you’re keeping goldfish outside, then they’re going to be even better as the winter months approach.

During this time, you’re going to need to feed them food higher in protein so they can build up stores ready for winter when they’re going to eat much, much less.

Blood Worms Are Good For Fussy Eaters

Blood worms are also great for fussy eaters. If you’ve got a goldfish that doesn’t eat a lot of food, you may have a lot more luck feeding them blood worms.

(Curious how long your goldfish can survive without food? Read here!). In fact, I’ve never had a fish that has turned its nose up to blood worms.

They Instigate Breeding

If you’re trying to get your goldfish to start breeding, then blood worms help to create the perfect environment to get your goldfish ready.

During the mating season, there’ll be an abundance of small insects and other meaty treats for your goldfish to eat, and you want to replicate this as best you can in the tank.

By adding blood worms to the tank, you’re going to help replicate this and increase the chance that your goldfish will breed together.

They’re Entertaining

And lastly, blood worms, as well as all live food, are entertaining for goldfish. They help fulfill the hunter instinct that all goldfish have.

(Find out if goldfish can eat bread.)

What Are The Downsides Of Bloodworms

As well as having some benefits, there are also definitely some downsides to feeding blood worms to your goldfish as well. Here are some of the reasons you may want to reconsider using blood worms as a staple part of your goldfish diet.

They Lack Essential Nutrients

While they’re high in protein, blood worms lack a lot of the essential nutrients that your goldfish needs to remain healthy. This is why it’s so important to make sure you’re only giving them to your goldfish as a treat and making sure they’re not a staple part of their diet.

They Increase The Chance Of Constipation And Swim Bladder Disease

If you give your goldfish blood worms too often, then you’re going to increase the chance of them suffering from constipation and swim bladder disease. This is because there’s not much fiber in blood worms, so it’s much more likely that they’re going to give your goldfish digestive issues.

They Might Spread Disease

When you add any live food to your tank, you’re going to increase the chance of diseases being spread. If you’re not getting your bloodworms from a reputable source, then they may not have been taken care of.

The last thing you need is for a disease to enter your tank, which could prove fatal to the inhabitants. So if you plan on getting blood worms, make sure you know where they’re coming from.

(Find out if goldfish eat frogspawn and tadpoles.)

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Different Types Of Bloodworms For Goldfish

Blood worms are stored in a number of different ways; you can get them frozen, freeze-dried, or live. And each different one is going to require different preparation before you feed them to your goldfish.

Here’s a little bit more on each of them.

Live Bloodworms

Live bloodworms are the ones you’re typically going to pick up in a shop. They normally come in a big bag, and they’re relatively cheap.

If you’re going to use live bloodworms, then you’ll need to make sure you use them within 2-3 days. After 10-12 days, their larvae cycle will be complete, and they’ll become midge flies.

When it comes to storing, make sure you’re storing them in a tub in the fridge with some water inside. This is the best way to slow the rate at which they grow to midges.

And lastly, your best bet with live blood worms is to feed them to larger tanks. If you only have a small tank or a couple of goldfish, then the chances are a lot of them are going to be left to waste.

Freeze Dried Bloodworms

If you don’t want to use live bloodworms, you can also try giving your goldfish freeze-dried bloodworms as well. The benefit of these is that they’re much easier to store. However, the downside is they’re the least nutritional.

Before feeding freeze-dried bloodworms to your goldfish, you should make sure that you’re soaking them in a little bit of the tank water first. This gives them time to expand. If they don’t expand beforehand, then the chances are they’re going to expand in your goldfish’s stomach.

(You should soak them for around 10 minutes.)

Frozen Bloodworms

Lastly, you can also try frozen bloodworms. These are a nice medium between live food and freeze-dried food. They retain a lot more of the nutrients than freeze-dried food does; however, they also last a lot longer than live food as well.

If you’re going to keep frozen bloodworms, then you can genuinely store them for about 6 months in the freezer.

If you plan on feeding your goldfish bloodworms, then you need to make sure that you’re defrosting them first. So, start by chipping off about half a cube per fish and putting them in a small container of tank water.

Once you’ve done this, leave them until they’re defrosted, and then add them to the tank.

How Many Bloodworms Should You Feed Your Goldfish?

If you’re not sure how many bloodworms you should feed your goldfish, you may end up under or overfeeding them.

Generally speaking, if you wish to feed them bloodworms, then 1-2 meals is enough before giving them a break. This is one of the reasons that it can often be better to buy frozen or freeze-dried blood worms.

If you add too many to your tank, then you’re going to increase the risk of your goldfish suffering from constipation and swim bladder disease. As well as this, any bloodworms that aren’t eaten might cause an ammonia spike in the tank.

How Often Should You Feed Your Goldfish Bloodworms?

If you’re planning on feeding your goldfish bloodworms, then less is definitely more. Bloodworms should never be a staple of your goldfish’s diet, and they should only be given as a treat every once in a while.

As a rule of thumb, you should only feed your goldfish bloodworms once or twice every couple of weeks. This way, you’re going to reduce the chance of them becoming sick.

As well as bloodworms, you can also try feeding your goldfish daphnia, brine shrimp, and mosquito larvae!


Now you know that while bloodworms can be fed to goldfish, they should only be fed to them every so often as a treat. It’s much better to feed them brine shrimp, mosquito larvae, or daphnia.

If you’re going to feed your goldfish bloodworms, you should only do so once or twice every two weeks. And make sure this is along with a balanced diet.

Bloodworms are great for your goldfish because they’re high in protein, they’re liked by most fish, and they condition your goldfish for birth. However, some downsides include the fact that there’s an increased risk of disease entering your tank as well as an increased chance your goldfish will become constipated or suffer from swim bladder disease.

If you liked this article, then make sure you check out the rest of the website! Otherwise, have a great day!

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