Bristle worms can be, and usually, are a real problem for reef hobbyists. Indeed, they create havoc in the aquarium, especially when they grow to larger sizes. Bristle worms grow quickly! Real quickly! They feed on anything they can find in the tank and grow to sizes that amaze most hobbyists. This process does not take long either.
Moreover once you have one, you actually can be quite sure that you have many of them as it is practically unheard of that only one is present in the tank. One is a sign that "they" are present. When I say "they" I mean a lot of them.
Whereas small bristle worms may look really harmless, larger specimens that have grown to sizes of 24 inches or more in length, are quite impressive and can cause serious damage. Remember too that the size you see is not necessarily the size of the worm. It may be retracted and look short and thick, but it can stretch itself to a real long size and be very thin. In either case it is a voracious eater and is carnivorous. It attacks corals, Tube worms, Christmas tree worms, rock anemones, and so on. In short it creates havoc in the tank.
In addition to feeding on left over foodstuff, small crustaceans, and detritus from which they extract uneaten parts, bristle worms attack corals and sometimes other animals too (anemones are a good example of the latter. Leather corals are another one).
Because of the damage they do, they absolutely need to be physically removed from the aquarium. This can be quite a task and is not as simple at it seems at first, as many of Hobbyists may have found out over time.
Most hobbyists are well aware of this, but just do not know how to go about removing them, or if they do, they are not too sure about all the details of the various methods described in magazines, some as the cure-all for bristle worms (which they often are not). Before being successful many attempts may be necessary (again, as many of you may have found out).
In addition, even if you catch a few of them, there may still be plenty more in the aquariu. Careful inspection of the tank, at night, with a red light, several hours after the main lights have gone off, will tell you whether or not there are any left in the tank, as they will be out at night, foraging and feeding. The red light is not really visible to them so they do not scurry away when you use. Make sure though that the room is totally dark besides the red ligth you are using (a red party bulb or a flashlight covered with red acetate will do the trick).
Let me dispel a myth: the small bristle worm traps that are sold in stores will often not work. The trap is either too small or it just does not live up to your expectations. It may trap some real small worms but it will, in the majority of cases, not trap the real large ones, the ones you really need to get rid of as they are the ones that cause most of the damage.
Home made traps work just as well as commercial ones. The method described here lets you build such a trap. And the one suggested here works. The only caveat is that you will need patience. Few worms will be caught at one time. If you have many, you may need to work with the trap for weeks to get all the bristle worms out of your tank. Unfortunately, I do not know of an easier way to do it. And believe me, I have tried many.
Many methods have been advocated in magazines to rid the aquarium of bristle worms. Most work but often a lot of patience is required before you actually get all the worms out of the aquarium. There are some that work better than others and those are the ones I will describe here.
You may have to try several before you actually have the success you wish. Not all methods work in all tanks and with all worms (note that there are many types of bristle and other carnivorous worms). Patience and perseverance are the key to success. This is often the case with reef tanks, not just for bristle worm removal. When one tries to go too fast, one makes mistakes and may stress corals and animals with the ensuing problems.
To find out whether or not you actually have bristle worms in the tank is not always that easy. It is even harder to do so during the day because they hide inside rocks and in crevices. They also hide in areas that are dark, behind and underneath rock and in the live sand you may have in your tank.
To determine whether any are present, the tank should be looked at during the night, several hours after the aquarium has been in the total dark. Even moonlight is a deterrent so you may need to close blinds or curtains and make sure the room is as dark as possible for several hours.
Bristle worms will come out in moonight type conditions, but more of them will come out when the darkness is greater, hence the suggestions to really ensure total darkness.
Note also that you need to look at the tank with a "red" light. No other light can be used because the worms will disappear as soon as regular light is used. They are sensitive to it and go into hiding. When red light is used they remain in the open, where you can see them.
Can you actually catch them while they are in the open? Some have tried by lowering wooden kitchen type tweezers into the tank very slowly and grabbing the worm. This method has worked but is not one that will help you get rid of all worms. You may however catch a few in this manner.
Mind you, when you look at your tank at night you may discover that you have plenty of other animals too, not just bristle and other worms for example. You really have (own) two tanks:
What you see during the day and what you see during the night are vastly different. Many animals that you will not see during the day will be out and visible during the night. Some corals, or small rock anemones that are photophobic (do not like light) will extend their polyps during the night.
In addition, the appearance of certain animals changes during the night, especially if they are night feeders (e.g Bubble corals).
To see the worms and other animals, the room needs to be totally dark too. Having just the tank lights off is not quite enough. The darker the room is, the better and the more creatures you are likely to see crawling and roaming around the aquarium. Often you had no ideas these were present in your tank. Why? Simply because they are night animals and do not show themselves during the day.
When approaching the aquarium with your red light, do so "slowly". Do not make brusk movements. Your presence and rapid movements "may" result in some of the animals you normally do not see during the day to go into hiding. Do everything in slow motion. Play it safe. The slower you move around the tank the better off you are.
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Checking for Bristle Worms
As indicated above this can only be done at night. You will rarely see a bristle worm during the day. They hide in rock and in crevices. They hide underneath rock, in the sand, behind rock and in any place where light is low in intensity.
The only way to determine their presence is to use a "red" light. You can make a red light out of a flashlight by covering it with a piece of red acetate or very thin red plastic material. This can be obtained for Arts and Crafts shops for a minimal amount of money. Tape it to your flashlight. Some package wrapping material is red too and can be used as well. Test the light you have made up in another room to ensure that it only transmits red light.
I may appear to insist on this, but if you are going to get up in the middle of the night to look at your tank, you may as well be sure that the light source you are using will allow you to do so and will not chase the animals you want to see back into hiding.
Besides Bristle Worms you may find that you see other undeserible animals crawling around, for instance Mantis Shrimp.
Once you have done all this, you are now ready to look at the tank in detail. Inspect all areas of the aquarium. Indeed, some of the live forms you may discover (in addition to Bristle Worms, are real small). You need to do so in total darkness and several hours after the lights have gone off. There should be no light in the room what so ever. It is a good idea to close your curtains or blinds too.
Inspecting the aquarium will show you that there are many more life in your aquarium than you actually imaged. Some of that life may be bristle worms or other undesirable animals. Some may be desirable and some may not be. I can not decide on that without knowing what exactly it is that you have.
Descriptions over the phone, or in email messages, usually do not help a lot in identifying such animals. It is too hard to describe exactly what you have. A photo sent to me though will allow me to give you an identification. A Polaroid shot is usually plenty, a regular photo will do too of course. You are welcome to avail yourself of this service we offer at no cost.
You can e-mail me if you wish: Mail your question to A. Thiel I will be glad to answer any questions you may have. Check other areas of our WEB site too, http://www.athiel.com as there are many articles you can download for free that may be of interest to you.
This, now, leads us to the actual removal process and the methods that you can employ to do so. There are several, as I indicated earlier. I will cover the ones that hobbyists seem to have the most success with. They are all geared to setting up some kind of a trap, but the traps themselves differ, and what is placed inside them may be different as well. I really prefer to make my own, as you will read later. This is not difficult at all and makes the whole process really inexpensive.
Try one of the methods and if you are not successful at removing the undesirable animals, try one of the others. What is really important in this whole process is patience. Do not give up too soon deciding that you are not able to remove the worms and other unwanted animals. You will eventually succeed but you must pursue the endeavor. If you give up too soon you have lost all you have accomplished as the worms will start reproducing. They do so rapidly too (just as they grow rapidly).
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Trapping the Worms and other Undesirables
Let us first discuss and list what kind of "traps" for worms and other animals you can set up and use. That will get us started, and you can decide which one you want to choose to start your first attempt at catching what you want to get out of your aquarium.
If the trap you select at first does not work, go to another type and continue you endeavor to remove the worms and whatever other undesirable animals you may have seen in the tank during your night inspection.
Below are various kinds of traps, from rudimentary to sophisticated ones. Choose the one that you think suits your purpose best (look at the cost too). Some you can make yourself, others are sold in stores and are prefabricated by manufacturers. Pet Stores and Mail Order places will have them available. You can check their ads in the magazines (e.g. FAMA, TFH, MFM, AF, and also in Aquarium Society Newsletters).
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Types and Kinds of Traps
All the traps described work on the principle that they are placed in the aquarium, in the area where you suspect there may be a worm (or several of them), and leave the trap there during the night (or for several nights in a row), after you have placed some food stuff in the trap to attract the bristle worm(s).
The key then is to find the right kind of trap, the one that seems to do the best job at trapping the bristle worms and preventing them from getting out of the trap. Although the "fancier" models may work, and may remove some of the undesirable animals, including bristle worms, I find that hobbyists seem to get the best results with home made models that cost very little and appear to be more effective than the more expensive ones.
Why they are more effective has to do with their design and with the fact that they often can be adjusted by the hobbyists according to what he or she wants to trap (as we shall see in the next section).
The way I suggest you trap worms and other animals you do not want, is to use such a home made model. I personally have nothing against the commercial ones but find the home made ones to work better. I will describe the process on how to build such a model below.
You can, of course, use some of the models described above and place food in them to attract the worms. That method may or may not work as I indicated. If the method you are now using that employs such a device does not work, meaning that it does not trap anything, try the home made models. In my experience and that of many others, those are the ones hobbyists are having the most success rate with.
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Home Made Models and how to Use them
Various type of home made models can be made. The difference has mostly to do with their size. You may want to start off with a small model and if that does not seem to work, upgrade to a larger one. Since you will be using very inexpensive materials (actually mostly food jars) the cost of changing from one model to another one is just about zero.
Another manner in which to change, and determine if you can trap the animals you want out of the aquarium, is to change the food stuff you place inside the container that is used as the trap. That often is better than making an new trap. Sometimes the type of food has a great deal to do with whether or not worms and other animals will enter the trap you set up.
If you have observed your aquarium at night, which you should have done, and know the approximate location (hiding space) of the worm(s), that is where you should place the trap, or at least as close to that area as you can. If there are different areas, you would want to move the trap around as you keep catching worms.
Note that besides bristle worms you may have noticed that your tank contains a Mantis Shrimp. The method used to catch it is the same as the one described for the worms. The only difference may be that you need to enlarge the holes in the container you use as a trap, to match the size of the shrimp you need to catch.
To make the trap, use a small plastic food container that has a lid. The container should be opaque, not transparent. You do not want the animal you want to catch to be able to see the food inside. You want it to have to crawl to the top of the container and then in the container to get to the food. The smell of the food is what should attract it, and make it do so. When the right kind of food is used, the animal will.
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What to put in the Trap for best Results?
The choice of foods I recommend you place in the traps are:
The size of the pieces of food that you place inside the trap need to be "small" but not minuscule. Too large pieces of food do not produce the result you and I are looking for. You can cut the fish food you use up (whichever of the above you use) with a knife, or put it in a blender and chop it up. Do not make the pieces too small either (no mush please). When using a blender, set it so the breaking up does not go as far as making a paste of the food.
When using a blender, a milky watery solution usually develops at the same time. Do not use it. It is laden with phosphates and will pollute your aquarium's water. You will then have to spend money to clean up the water before green filamentous and/or slimy algae start growing. Don't add pollutants to the tank that you later need to spend money on removing. You can avoid doing so by not adding the liquid.
Place a small amount of food in the container and make sure it remains at the bottom. By small I mean pea size to two pea size maximum. Do not put more and if you do not catch bristle worms in the first 48 hours replace the food with fresh one. If you do not, the food will start to decay and pollute the water. As a matter of rule, the food should be changed every 48 hours at least. Changing it more frequently is fine of course.
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How to Fabricate the Trap
If the container/trap you use is not working -meaning if you do not catch anything- change the food you put place in it and make the cut in the lid either smaller or larger, depending on what you are trying to catch. Sometimes the cut is too large and the worm or other animal gets back out, sometimes it is too small and the animal cannot get in. Adjust the size of the cut and eventually you will catch what you are after.
There is no magic formula. You will need to adjust the size of the openings and the selection of the food as often as is needed for you to start having success. Meaning you are catching worms and so on. If you catch animals that you do not want to remove from the tank, just let them out of the container and release them in the tank.
The kind of jars to use are the small food type ones, often white with a pop-on lid. Many foods in deli departments are sold in such jars.
As I said earlier, should you have any questions about this article, do not hesitate to send me your questions as eMail:
If you have any suggestions that you feel would be helpful, please send them to me too. I will add them to the article.