ARK - Arizona Rivulin Keepers

A Yarn About Yarn

By Allan Semeit, this article was originally published in "Tropical News," the monthly magazine of the Sacramento Aquarium Society in November 1994.

You have probably seen a variety of gimmicks on the market to help people lose tension and relax. One that will not surprise any aquarium hobbyist is the fish tank in the waiting room of your doctor or dentist. It is a fact that just watching fish swimming around in an aquarium helps to relieve anxiety.

Another stress reducer, one that is certainly less known, is the making of a spawning mop. Yes Martha! You know what I am talking about: those fake substitutes for live plants, roots, and stratum; that artificial stuff in which many fish will lay their eggs. While these are anathema and totally unkosher to some aquarium purists, spawning mops have their place.

Spawning mops offer some real advantages to breeders of egg scattering fish like tetras, danios, barbs, killifish, and some catfish, to name some. First, if you use a "spawning tank," it is probably bare except for a spawning mop and possibly a filter. When checking to see if your fish have deposited their eggs in the mop, you can easily remove the mop from the aquarium. Second, you can keep a spawning mop on a poorly lit aquarium without worrying about it dying and polluting the water, something that might happen if you were using live plants. Third, a spawning mop can serve admirably as a hiding place for adults and fry in confined quarters. Fourth, if you try to breed your fish in a community tank with real plants, you may face a real chore in removing the plants without totally tearing the tank apart.

It is incredible to see the number of ways a spawning mop can be made. For some, it approaches being an art form. I have seen instructions that direct you to tie intricate knots or carve grooves in cork. Frankly, I am too impatient for those techniques and like to make my mops as simple as possible.

Personal experience over the past 20 years has revealed that the hardest part to making a spawning mop is finding the right yarn. It seems like every general merchandise store carries a variety of colors and compositions. This is multiplied when you consider that every store seems to offer different brands, all of which vary to some degree. I tried a variety of compositions and colors and keep coming back to dark green "orlon acrylic." This is not to say that some other composition or color might work better for you.

"Orlon acrylic" yarn is extremely common, but much of what you will find is not suitable for aquarium use. Why? There are several reasons. Some yarns "shed" and clog up your filters. Some are poorly dyed and you cannot stop the color from bleeding, no matter how long you boil it or even when you add vinegar to "set" the color. However, the most common reason for rejecting a yarn is that it is "mothproof." Mothproof used to mean that the yarn had an insecticide added to it, although it could also mean that the fibers are synthetic and moths cannot eat them. Your best bet is to be safe and avoid any yarn labeled "mothproof." All of this means that you will have to shop, read, and experiment to find the right yarn for you.

Once you find a good yarn, chances are you will not find it again. Stores change their stock and buy from a variety of manufacturers. The manufacturers also change their colors regularly. By the time you find that you have obtained the "right stuff," you may not be able to find any more.

Assuming that you have acquired some yarn, what is my easy (or lazy) way to make a spawning mop? Find a hardbound book about 8-10 inches from top to bottom. Run a strand inside the front cover, running from bottom to top, and then keep wrapping the strand around the book. After about 80 turns, I stop. Grab some scissors and cut the strands across the bottom of the book. Take all of the strands and lay them flat. Find the midpoint and separate one strand and use it to tie the rest. I try to balance the lengths equally on each side of the tying strand. Use a square knot and wrap the tying strand several times before tying another knot, and continue this until you run out of tying strand. You can trim off any piece of the tying strand too short to tie.

After you tie a spawning mop, the next step is to boil it. Using an old pot, boil the yarn. This is done to bleed excess dye. Usually the color stops bleeding by the third or fourth time you boil, drain, refill the pot, and repeat the process. If the yarn continues to bleed, try adding some vinegar when you boil the yarn. If color continues to leach out, donate the rest of the yarn to your cat or charity, and try another brand.

After the boiling step, you have successfully manufactured a "bottom" mop. Once it has cooled, you can use this as spawning stratum for fish who prefer to lay eggs on or near the bottom of the aquarium.

Converting a "bottom" mop into a "top" or "floating" mop is simple. Find the middle of the mop where you tied it, drape this over a flotation device, and fasten with a rubber band. The flotation device can be almost anything. I have used old pill bottles, corks, and styrofoam balls that you find in craft stores. The advantage of using a rubber band is the ease of conversion from a bottom mop to a top mop and back again. The only drawback is that rubber bands eventually fall apart, but they are cheap and easily replaced.

As you can see, the mop making process can be very simple. If you are more creative or a perfectionist, you can use other methods. The end result is that spawning mops can be very beneficial to the tropical fish hobbyist and the manufacturing process can be quite relaxing. Why not try it?