Grindal worms (Enchytraeus buchholzi) are a small white non-parasitic worm that lives in soils around the world. They are similar to White worms that are commonly used by other aquarists as a source of food for their fish. However, these worms are smaller than White worms and their care differs slightly. Grindal worms are a great food source to feed your young fry and adult fish that stay under a couple of inches. This species was discovered by Mrs.Morten Grindal of Sweden who was attempting to improve her White worm culture and stumbled upon these small worms by accident.

So, you might be thinking why should I bother with Grindal worms? What makes them a good food source for fishes? What I like about Grindal worms are that they are easy to take care of compared to other live food cultures. Most other food cultures tend to have special requirements and are more time intensive.

Take for instance White worms, these worms require lower temps to successfully culture and can easily die on you if kept at room temperature. Grindal worms, on the other hand, reproduce best at room temperature (70-75F) and are able to handle hotter and cooler temperatures if need be. This makes them an ideal candidate to culture long term and are less of a hassle to deal with. Along with this, they require little maintenance and little space to have a successful growing colony.

Grindal worms make a great food source for any picky fish that require live foods. There are two added benefits for using live foods. One of these benefits is the ability to gut load these guys with veggies and other food sources to help ensure that your fish have a mixed and varied diet. The other benefit is that live foods help induce breeding behaviors in fish. A lot of the time, the reason why your fish aren’t breeding is due to lack of a proper food source.

Grindal Worms are rather easy to culture. There are various ways to culture these little worms. But, from my experience, the best foolproof way with more yield is to use the supplies listed below.

You don’t have to be too fancy with this. A simple plastic container works great! I found mine at Walmart, but there are some similar containers on Amazon. Of course the bigger the container the more worms you can gather and the more stable the colony will become. I would recommend the top of the container have some type of ventilation to allow for oxygen flow. Simple air holes will be fine. I have found that a lot of ventilation will help your colony grow faster but the coconut fiber will dry out sooner meaning you’re going to have to spray more water to keep the soil damp.

Also, if these holes are really big, I recommend that you plug them up with aquarium floss or something equivalent to prevent other critters getting into your culture. Trust me, you don’t want fruit flies or mites sharing a breeding ground with your new wormy buddies.

You need something for your Grindal worms to live in. People use a wide arrange of substrates. The more common ones being potting soil, peat moss, and coconut fiber. In my experience, Coconut fiber works best. Potting soil and peat moss can be somewhat acidic and may hurt your Grindal worms. Along with this, potting soil is prone to have other pests in the substrate. The coconut fiber that works best for me is the Zoo Med Eco Earth Compressed Coconut Fiber Substrate.

This coconut fiber has a lot of bang for the buck. Simply add water to dampen the coconut fiber and watch it expand! Also, there is a lower chance that these blocks will have unwanted pests. Whichever route you take you want the media to be damp enough that it clumps a little but not a sloppy mess. Your worms will drown if you have too much water and dry out if you don’t keep the substrate wet enough.

Yes, that’s right. Your worms are going to need some food. The best type of foods would be grains, fish food, veggies, and fruit. The stable of Grindal worms would be dry foods items such as dog food, white bread, cereal and fish flakes. All of these work wonderfully. I would suggest that with dry foods you should wet them slightly to make them easy for your worms to break down.

Veggies and fruit should be treated as treats. Make sure you stay away from fruits with high amounts of citrus as these might be too acidic for them. Don’t feed too much! You want to feed as much as they can eat in a day. Too much food will lead to mold problems and potentially mites and fruit flies. Just play it by eye and adjust as necessary.

What I typically do is have a piece of plastic canvas and place the food on top of it. As the worms gather to the food source I simply remove the food and dip the canvas into a small cup of aquarium water. With a small pipet, I suck up worms and try not to get any debris and simply squirt it into the fish tank. These worms can live a couple of hours in the water so don’t be alarmed if you feed your fish too much.

Grindal worms are hermaphroditic. Grindal worms produce small yellowish cocoons that house eggs. These worms reproduce readily if given the correct parameters. No need to purchase multiple cultures after you have your first successful colony growing.

You can expand your culture at any time after the culture establishes itself. Just make sure you aren’t feeding your fish too much. This is why it’s advised to have extra cultures on hand if you exhaust your culture too fast or the culture crashes. Simply, gather some worms, get a new container, add bedding and food and wait for the new culture to reproduce. I would also suggest that every couple of months you should split your cultures so that they have access to new fresh bedding.

If you do happen to find your culture heavily infested with mites or fruit flies there is an extreme option you can take to rid yourself of these pests. I would collect as many grindal worms as I can and place them in a cup of water. The grindal worms should sink to the bottom of the glass, while any mites or eggs will float to the top of the water. Gently pour out small amounts of water at a time. When you feel like you've removed all of the mites and eggs from the cup you can start a new culture from the worms you saved. Don't worry about the grindal worms drowning, they can last a while underwater. To prevent future outbreaks of these pests I suggest that you have a tight lid on your culture along with some aquarium floss in the ventilation holes to prevent bugs from entering your culture.

If your girndal worms start to give off a foul smell, it might be a sign that your culture is getting old and you need to split it and start a new culture. Another reason might be the food that you're using is not being eaten fast enough and spoiling too soon.

Grindal worms can be found at your local fish clubs, other fish hobbyists, Mom and Pop Fish stores or over the internet.