Bloodworms 101: Frozen, Live And Freeze Dried

If you’ve been in the aquarium scene for long enough then you’ve undoubtedly heard about bloodworms the basics about how they’re used.

But past that, most people know very little about them.

What are the different types you can feed your fish? What do bloodworms eat? What fish prefer them?

In this info guide, we’re going to answer all of those questions and more. As you learn more, you’ll see that bloodworms can be a tremendous asset to help you maintain a healthy aquatic ecosystem.

What Are Bloodworms Used For?

In case you’re unsure about the purpose of bloodworms, the answer to your question is very simple.

Bloodworms are used for food.

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A wide variety of fish and aquatic life will happily eat this worm and benefit from the rich protein and nutrients they provide. This is the reason they’re so popular, pretty much everything finds them tasty!

Different Kinds Of Bloodworms

One thing that’s important to remember is that you can feed bloodworms to your fish in a few different ways. Just like the food you buy at a store, it can come prepared in different ways.

Each of these ways carries unique positives and negatives, which we’ll explore below.

Live Bloodworms

Live bloodworms are a popular option that aquarists tend to consider. These worms are alive (obviously) and the buyers of this tend to like the idea that they are giving fish food in a more natural way.


  • Live bloodworms tend to be fresher than frozen or freeze-dried options
  • They are very rich in vitamins and nutrients compared to other forms
  • Feeding your fish live bloodworms will often bring out a more active side and can be quite fun to watch (compared to flakes).
  • They can be useful if you are “conditioning” your fish before breeding. Giving them nutrient-rich food is a great way to make this happen.


  • You can’t store them for as long as other forms. You typically have a window of two or three days that you can use them as food before they die.
  • There’s a little more prep involved to make sure they are ready to be eaten
  • Using live bloodworms comes with an increased risk of potential disease and sickness for the animals that eat them

Frozen Bloodworms

Frozen bloodworms are definitely the most popular form of bloodworms that aquarists use. This is mainly due to the convenience, but here are the pros and cons to give you the big picture:


  • You can store them for almost half a year in your freezer
  • The risk of disease is extremely low, so feeding them to your fish is very safe
  • Frozen bloodworms allow you to either feed your tank in one condensed area or spread it around the whole tank


  • There won’t be as much activity during feeding time
  • You have to wait for frozen bloodworms to thaw before feeding time
  • There is a chance that it can increase the bioload of your tank since 100% of the frozen bloodworm won’t be eaten

Freeze Dried Bloodworms

Freeze dried bloodworms are another very common and convenient form of bloodworm that is used by many tank owners.

San Francisco Bay Brand Freeze Dried Bloodworms

  • 100% pure high quality bloodworms
  • No fillers or residue
  • Clear container so you can see the quality
  • A fish favorite


  • Are definitely the easiest kind to feed to fish.
  • You can get them in different quality grades which allows you more control over the feeding process


  • The least healthy and nutritious option out of the bunch
  • You need to spend some time soaking them to allow them to sink if you have fish that spend their time on the bottom of the tank.

What Fish Eat Bloodworms?

This is one of the most commonly asked questions when it comes to bloodworms, and it’s one of the easiest to answer. Bloodworms are the perfect snack for your fish and will get eaten no matter what form you serve them in.

And when we say pretty much all fish, we mean it.

Both saltwater and freshwater fish will scarf down bloodworms without hesitation. This means you likely don’t even need to consider diet compatibility when it comes to your fish.

With that being said, there are some fish that seem to enjoy these more than others. They are:

If your fish isn’t on this list don’t worry about it. Chances are they’ll enjoy bloodworms too!

However, there is one thing you need to be aware of…

Don’t Go Overboard

Despite the fact that they’re considered a tasty treat by pretty much all fish, feeding them bloodworms too often is something you should avoid.

The reason for this is that bloodworms aren’t a complete food that covers a range of vitamins and nutrients. They have a TON of protein and iron in them, which is great. But that’s about it.

In order for fish to thrive, they need to have a balanced diet (just like people). Feeding your tank bloodworms exclusively (or too often) can upset this balance.

The general rule of thumb is to give your fish bloodworms once or twice a week. If you stick to this rule and provide them with a well-rounded diet then you’ll be just fine.

Where Can You Buy Bloodworms?

You have a number of different options for places to buy bloodworms. You can try your local pet store (assuming it carries aquarium food) but that can sometimes be hit or miss.

If you want to buy locally your best option is a fish or aquarium shop. Bloodworms are so popular that we’ve seen them at the majority of aquarium stores we’ve been to.

The one thing that might vary is the state of the worms you purchase. Frozen bloodworms and freeze dried options are very common, but if you want them live then that might vary based on the store.

A lot don’t want the hassle of having to deal with them live and prefer to stick with kinds that they can store cheaply for a long time.

If you’d rather go with a cheaper option that gives you a little more convenience, then here’s what we recommend:

Buying Bloodworms Online

Getting your bloodworms online is something we highly recommend if you’re looking for the easiest and most affordable way to go (Amazon is best).

Author note: If you’re already sold on this as the best choice for you, give San Francisco Bay Brand Bloodworms a shot. They’re our favorite by far.

The prices are favorable compared to local aquarium shops which really adds up over time if you plan on feeding a significant amount of bloodworms to your fish. Fishkeeping isn’t cheap, so anything you can do to cut costs is worth considering.

Here’s the catch:

You can pretty much only get freeze dried bloodworms if you’re shopping for them online. This is fine for most people, but if you had your heart set on live or frozen bloodworms then it might not be the method for you.

In our opinion, having to stick with freeze dried is not a big deal nutritionally. Although they aren’t as rich in nutrients as the other two options, you should be using them to supplement your fish’s diet.

Assuming this is the case, then you can still provide your fish with a great boost in protein and iron while enjoying the convenience of online ordering.

There are a lot of freeze dried bloodworms you can get online, and most of them look pretty much the same at first. Because of this, it can be hard to figure out what product is best.

San Francisco Bay Brand Freeze Dried Bloodworms

  • 100% pure high quality bloodworms
  • No fillers or residue
  • Clear container so you can see the quality
  • A fish favorite

Fortunately, we’ve done that for you. We’ve tested a variety of bloodworms and sourced feedback from other aquarists we trust in order to come up with our favorite product.

So here they are:

San Francisco Bay Brand freeze dried bloodworms are the brand that we recommend to everyone. They’re an extremely high-quality choice that has been trusted for years by highly experienced aquarists.

Not only that, but they’re packaged safely and efficiently, and the nutritional quality is top of the line.

Growing And Breeding Your Own Bloodworms

If you’re considering breeding your own bloodworms to save money over time, there are a few things you should know first.

While it seems reasonable to assume that breeding and growing bloodworms would be easy, it’s actually very challenging. The reason for this is that you need to see them through their lifecycle until they become full-grown flies.

These flies can be difficult to manage because the necessary conditions they require to mate are surprisingly precise. Also, it’s quite a process to keep a bunch of flies in one area without them getting out (and making sure they’re actually mating).

For this reason, most aquarists prefer to simply purchase their bloodworms from a store or online. It can be time-consuming enough to maintain a healthy tank, and dumping a ton of time into your worms can quickly turn things from a hobby into an unpaid job.

What Do Bloodworms Eat?

Since bloodworms are midge fly larvae they will eventually grow up to be adult midge flies. Once this happens the dominant source of its food will be fresh blood as a source of protein. 

This is not something you’ll have to worry about if you purchase bloodworms in the forms we listed earlier.

Do Bloodworms Bite?

This is a common question because Glycera bloodworms do indeed bite. In fact, they have a venom gland that can result in a reaction very close to a wasp sting (they also look quite spooky when they do bite).

However, this is not the kind of bloodworm that you’ll be dealing with are typically not Glycera. Like we’ve mentioned earlier, they’re actually red larvae midge flies!

Where Do Bloodworms Live?

The Glycera type of bloodworm usually lives in shallow marine waters. Red larvae bloodworms (the kind we’re talking about in this guide) usually come from moving water like large rivers and streams, or lakes and ponds that have a lot of organic material.

Now You’re Ready To Go

You should now have the necessary knowledge to start introducing bloodworms into the diets of your fish. Reading this guide will help you avoid making any dietary mistakes or picking a low-quality product.

Remember, fish love bloodworms so it’s up to you to keep their consumption at a moderate level.

If you have any questions or suggestions for different bloodworm products we might want to investigate just let us know!

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