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Eco-Friendly Fishkeeping

You can use aquarium water to water terrestrial plants. Photograph by StockLite/Shutterstock.

Earth Day is a great time to carefully consider the impact our hobby has on the environment, and what we can do to lessen that impact. During my tenure here at TFH, I have learned about a few eco-friendly ideas that you might want to implement at home.

  • Aquarium water from a freshwater tank can act as a great natural fertilizer for plants. Whether you have a huge outdoor garden or a single plant indoors, it is worthwhile to use water taken during a water change for your plant instead of pouring the water down the drain. As a bonus, you can save money on fertilizer too!
  • If you don’t have plants, there are other ways you can save water. A good one is to use the water taken during a water change to flush your toilet. Just be aware that aquarium water can make your toilet look dirty.
  • Newer technology can help save energy while operating your aquarium. For example, LED lights use far less energy than other forms of lighting. You’ll also save money on your electric bill!
  • Choosing to buy captive-bred species instead of wild-caught ones will help the environment in many cases. For example, Banggai cardinalfish are on the verge of extinction in the wild, so buying captive-bred can literally mean the difference between preserving a species and helping to push it over the brink of extinction.
  • Along the same lines, only choose to purchase species you know you can keep. No matter how beautiful the fish is, if it won’t eat what you’re offering, grows too large for your tank, or is too sensitive to be kept in captivity, it is never the eco-friendly choice!

Do you have other aquarium-related eco-friendly tips? Let us know in the comments!

Posted October 12th, 2014.


Diving St. Martin

By Shari Horowitz

Whenever I have the opportunity, I opt to go and visit fish in their natural environment. So when I went to St. Martin on vacation, diving was the number one activity on my list. After meeting Sally Davies, co-owner of Octopus Diving in Grand Case, on the French side, I booked six dives with Octopus and went straight there on my first full day on the island.

St. Martin largely features shallow-water diving, with the maximum depth I went to being 60 feet. The reefs primarily feature huge sponges and sea fans, along with hydroids and encrusting coral. The water is quite warm, and I only required a 3 mm wetsuit. There were no difficult currents and the weather when I was there was perfect.

From what I could see, the most abundant fish on the reef were sergeant majors, which patrolled the reef by the thousands. Reefkeepers know sergeant majors as extremely belligerent damsels which can reach up to 10 inches in length. On the reef their aggression is on full display if you choose, like I did, to try and find their nest. It’s easy to find breeding males, as they turn bright blue instead of the normal yellow and black coloration. However, be warned, that if you pester a blue male it will have no hesitation about chasing or even nipping you. I was chased quite a bit, but I managed to find the nests they were guarding so I think it was worthwhile.

Closer to the substrate, another common fish is the Atlantic blue tang. Atlantic blue tangs are another hobby staple, as they are beautiful and reliable algae eaters. They spend their entire day on the reef picking at the rocks and sand looking for algae. One thing to note is that they do reach a large size of well over a foot, and you can see many large specimens on the reef.

The Atlantic blue tang caused the most memorable moment on the reef during the trip, which actually occurred while snorkeling. The tang was pestering an octopus off Creole Rock, and so the octopus changed from a dark brownish red color to a mottled white and green color. Then it noticed that I was watching. Now doubly annoyed by the clumsy human above and the tang below, the octopus performed a veritable light show, going from white to green to red to brown and every combination in between. After diving for over 10 years, I admit that I had never seen anything like that and the octopus’ display alone made the entire trip worthwhile.

By the end of the trip I saw many other aquarium species at dive sites like Turtle Reef, Japanese Garden, and the Tugboat. Goatfish, butterflyfish, and hogfish were plentiful, as were chromis. I also saw species that get far too large for an aquarium. Impressive-looking barracuda stared me down, daring me to come too close—I kept a respectful distance. Green morays with a girth almost as large as my tank lurked in man-made reef blocks, along with some of the largest reef lobsters I had seen. At the surface, a few green sea turtles came near the boat.

St. Martin is a beautiful, easy place to dive, and an excellent place to see some common aquarium fish enjoying their natural habitat. I’d like to thank Octopus Diving—Sally, and the two divemasters who led the dive tours Craig and Sean—for a great experience.

All photographs courtesy of Sally Davies/Octopus Diving

Posted January 4th, 2013.

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Ancient Oceans

The Milstein Hall of Ocean Life at the American Museum of Natural History. Photograph by Denis Finnin / AMNH.

Walking into the Milstein Hall of Ocean Life at the American Museum of Natural History is an experience unlike any other—right at the entrance is a 94-foot long model of a blue whale. This iconic piece of New York scenery is just one of the many life-like displays in the hall itself. Having last been to the museum when I was a kid, it was enjoyable to see the exhibits from an entirely different perspective.

A fossilized relative of the horseshoe crab.

One of the things in the hall that caught my eye was how many species that are so prevalent today were found in ancient seas. For example, there was a fossil of a close relative of the modern horseshoe crab showing the crab walking along a trail before ultimately dying. Horseshoe crabs are somewhat uncommon in aquaria, but as “The Reefer” columnist James Fatherree wrote, they can live for up to 10 to 15 years in captivity.

Diorama of life in the Ordovician Seas.

There were also several dioramas replicating ancient seas. The one showing the Ordovician Sea covered an area that is now Ohio! It featured a relative of squid and an ancient arthropod. Although squid are not typically found in modern-day tanks, arthropods are immensely popular in the form of crustaceans.

Nautilus relatives were prominently featured in Cretaceous Seas.

Next to the Ordovician Sea diorama was the Cretaceous Sea one, which showed a section that covers modern-day Tennessee. An ammonite, an ancient, extinct relative of the nautilus, is prominently featured in this display. For experienced aquarists only, nautiluses can make a unique species only setup, as described by Bob Goemans in the March 2009 “Invertebrate of the Month.”

Next time you are looking into your tank, maybe you’ll see something that reminds you of ancient seas and maybe you can even learn a bit about the history of your animals. One great place to start as at the Milstein Hall of Ocean Life at the American Museum of Natural History.


Posted February 17th, 2012.

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Stocking A 10-Gallon Community Tank

The celestial pearl danio is a great choice for a 10-gallon tank. Photograph by Gary Lange.

By Shari Horowitz

The 10-gallon community tank is among the most popular for beginners, but few of them know how to stock it correctly. In many ways, stocking a 10 gallon is harder than stocking, say, a 55-gallon tank. Here are some tips to keep in mind, along with some fish to keep.

How Big Does It Get?

We say this all the time in the magazine, but it still bears repeating: How big will your fish grow to? An oscar that grows to well over a foot in length will never be appropriate for a tank that is 20 inches long but only 11 inches wide—how will it turn around?

Good choices are fish that stay fairly small, including various tetras, livebearers, dwarf cichlids, and dwarf gouramis.

What Level Does it Occupy?

Keep in mind the level of the tank each fish species will occupy. Having a bunch of fish dashing across the middle of the tank is not as visually compelling as having some fish flitting about the surface, some playing in the middle, and a bunch crawling around on the bottom.

For example, hatchetfish (both marble and silver), African butterflyfish, and glass catfish will all stay at the surface of the tank. Cory cats, Otocinclus catfish, and loaches, all pretty much remain on the bottom.

What Is Its Personality Like?

Even as a small juvenile, the oscar mentioned earlier would be ill-suited to a 10-gallon community because of its aggressive nature. Generally speaking, 10-gallon tanks should have peaceful fish or become a species tank, as the small space allows less aggressive species fewer opportunities to get away from or hide from their tankmates.

Most livebearers are peaceful as long as only one male is included of each species, as are many species of tetras, cory cats, rasboras, and oto cats.

How Many Can You Keep?

Even the most peaceful fish can become aggressive if it is crowded in with far too many neighbors, and in a 10 gallon, that is all too likely a possibility. The number of fish you can keep depends on the mix of species and the ultimate size each fish can reach.

For example, you might be able to keep a dozen or so neon tetras in a 10 gallon because neons reach slightly less than an inch in length and are very slim-bodied animals. Conversely, you might only fit two dwarf gouramis because they reach 3½ inches in length and have much deeper bodies than the tetras. You can include both fish in the same tank, since the gouramis prefer the surface and the tetras are more mid-water swimmers, but then you would reduce the number of tetras to somewhere between five and seven, as that should give everyone plenty of room to move around.

Plan Ahead

One of the best ways to find out what works is to see if it has worked in the past. Find out what has worked for other people. Also, look up everything you can about the fish you want to keep. If you plan ahead, you can create a great 10-gallon tank!


Wood, Kathleen. 2007. Adventurous Aquarist Guide: The 101 Best Tropical Fishes. T.F.H./Microcosm Professional Series. Neptune City, New Jersey.


Posted December 16th, 2011.

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Giving the Gift of Fish Part 2

Photograph by Alexander A. Sobolev/Shutterstock.

In my last entry about giving fish as a gift, I recommended giving only the hardware for a fish tank and waiting to obtain livestock. If you do want to give actual fish on the holiday, you could cycle the tank beforehand, keeping it hidden. Either way, wait until there are no ammonia or nitrite readings from water test kits, and there is only a small amount of nitrate (up to 20 ppm), before adding any fish or other animals.

Once the tank is ready for animals, talk with the child about what type of fish or invertebrates they want. Review the different things that must be taken into consideration before choosing what animals will go into a tank: the tank size, the size of the fish, their temperament, their habitat, any special needs, etc.

It is best to have a plan before going to a pet store. One way of making things easier is to have the child pick a “must have” fish, the one that they want most, and, as long as that fish is appropriate for the tank that you have, you can pick tankmates from there. Feel free to talk with the store employees as well; they often have a very clear idea of what fish work well together and, more importantly, which ones don’t. Be sure not to purchase too many fish at one time—the newly established biological filter can be easily overwhelmed if too many fish are added at once. However, you can decide which fish you will come back for at a later date.

Since this is a brand-new tank, you can treat the entire aquarium as a quarantine unit. If you choose to add fish later, however, you will have to set up a separate (often smaller) tank to quarantine the new additions. After coming home with your new acquisitions, help the child acclimate the fish to your water. Have them float the bag containing the animals in the tank water to equalize the temperature. Then slowly add new water to the fish’s container, allowing them to get used to the new water parameters.

Now is the most fun part—carefully add the fish to the tank and watch them explore their new environment! Be sure to check for any seemingly aggressive interactions, any signs of disease, or other issues, and have a hospital/quarantine tank on hand if any action is necessary. But other than that, you and the child can enjoy the tank together for years to come!

And to help them keep learning about all different types of fishkeeping, improve their skills, and expand their hobby, be sure to get them a gift subscription to Tropical Fish Hobbyist Magazine.

Happy Holidays!

Posted December 15th, 2011.

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Giving the Gift of Fish Part 1

Photograph by Kakigori Studio/Shutterstock

Do you know someone who is wishing for a new fish tank this holiday season? Do you want to be the one to deliver that amazing gift? Every year, many fish tanks are bought as presents but, unfortunately, they are either not set up properly or neglected after a period of time, which oftentimes leads to the loss of the fish. However, this doesn’t have to be the case—fish tanks can and should be fun and educational gifts with rewards that can last a lifetime. Stick with TFH and learn how to avoid the common pitfalls of giving a tank as a gift.

First and foremost, if you are getting an aquarium for a child and you are not that child’s parent, please make sure the parents are onboard. No matter how responsible a child is, the parents are mostly likely going to have to help out with the aquarium at some point, and you have to make sure that they are willing to do so.

Perhaps the most common mistake that people make is trying to give the fish and the tank together. Putting fish directly into a new tank leads to “new tank syndrome”—a situation in which harmful nitrogenous wastes, especially ammonia, build up because there are no beneficial bacteria in the tank to consume them. Ammonia is toxic to fish and is one of the leading causes of fish losses.

In order to avoid new tank syndrome, you must first cycle a tank, allowing the population of nitrifying bacteria to build up before adding any livestock. One great option is to give all of the hardware and other materials needed for an aquarium, but no fish. Spend some quality time setting up the tank, stand, filter, heater, lights, hood, and any pumps or other accessories you would like. Rinse the gravel along with any rocks, driftwood, or other ornaments, and soak the driftwood as necessary. Show the child how to use water conditioner, explaining that tap water can have harmful chemicals that the water conditioner removes. Also, be sure to explain that the water temperature of the replacement water must match the temperature of the water in the tank.

Once everything is up and running, and the tank looks exactly how you want it to, explain that the tank must cycle before fish can be put in there. If you have an aquarium, add some used filter media, gravel, and/or plant cuttings to the new tank to jumpstart the cycle. You could also buy a proprietary starter culture. Add fish food to the tank and let it decompose to serve as a food source for the bacteria. Run water tests on the tank daily; it should show a spike in ammonia first, then nitrite, and finally nitrate. Once there are no ammonia and nitrite readings, and only low levels of nitrate, it is time to add fish.

This can also be a great time to give the child a general book about aquarium keeping, such as the Simple Guide to Freshwater Aquariums (T.F.H. Publications, 2001), and/or a gift subscription to a reliable aquarium magazine, such as Tropical Fish Hobbyist. Have them read up about aquariums before obtaining any fish. Check out my next entry to find out about choosing and adding fish to a tank.

Happy Holidays!

Posted December 14th, 2011.

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Beauty of the Sea

Photo Credit: Wolcott Henry/National Geographic

Every time we look into a marine tank, we are instantly reminded of the beauty contained within our oceans. Beauty is, of course, one of the many reasons to keep a fish tank at all. So I guess it should not have come as a surprise to me, when I was looking at National Geographic’s Top Ten Nature Galleries of 2011, that six of the ten galleries were focused on aquatic life. Megafishes, Colossal Sea Creatures, Deep-Sea Creatures, Dangerous Sea Creatures, and Colorful Sea Creatures all topped the list.

Now, obviously huge fish and other giant sea creatures are inappropriate for tanks, and deep sea creatures are not collected for the aquarium trade, but both dangerous and colorful sea creatures are often kept. In fact sea anemones and surgeonfish were on both of those lists. They also included clownfish, moray eels, mantis shrimp, angelfish, and sea stars.

I think these lists can serve as a great reminder that not everyone is lucky enough to see the beauty contained within the oceans all the time, but many people are still interested in looking at them. Personally, that’s why I like to keep a display aquarium out where everyone can see itit serves as an ambassador for the habitat it represents in an interactive, entertaining, and beautiful way.




Posted December 7th, 2011.

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Changing Seasons

Ram cichlids are found in the Morichal River. Photograph by Ivan Mikolji.

By David E. Boruchowitz

I saw my first vee of geese flying south this morning. I’ve heard a few before, but this is the first one I saw. For us in the Northern Hemisphere the geese are iconic of fall—shorter, cooler days and magnificent foliage. We are so linked to a climate with abrupt changes in temperature that we often think of the tropics as homogenous, unchanging. But the tropics have profoundly different seasons: dry and rainy.

In many ways this bipolar seasonal change is greater than the ones we experience. A fish that in the dry season hides in the leaf litter under a stream bank might be swimming among the leaves on high branches of mahogany and teak trees in the rainy season. Fishes are adapted to such changes that include factors like temperature, water chemistry, strength of currents, available foods, risk of predation, and spawning sites.

TFH contributor Ivan Mikolji has on his website photos of given locations in both the dry and the rainy seasons that illustrate nicely how different the habitats can become:

It is therefore a mistake to think of freshwater tropicals as inhabiting a stable habitat as reef fish do. Very few freshwater aquarium species experience the temperature extremes of a temperate climate, but they experience equally dramatic changes in their environment throughout the year. Our seasons govern when fish spawn, with many species needing a cooling period and then spawning when the temperature rises again. In the same way, tropical seasons typically determine when tropical fish spawn. Very often simulating some aspect of the dry-rainy cycle will persuade reluctant breeders. Increased water changes, plenty of live foods, and a slight drop in temperature may mimic the rainy season’s flooding, while decreased changes and a rise in temperature can simulate the dry season.

So, while our own seasonal changes have us checking heaters and putting up storm windows, they should also remind us that our fish might benefit from some changes in environmental conditions as well, especially if we’ve been frustrated trying to get them to spawn.


Posted October 5th, 2011.

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Wisconsin Weekend

A rasbora community. Photograph by Tony Terceira.

By David E. Boruchowitz

I just returned from Wisconsin, where I talked about nano tanks with MAS (the Milwaukee Aquarium Society) and the next day with MAAH (Madison Area Aquatic Hobbyists). I was treated regally and thoroughly enjoyed myself!

I had already caught the nano bug when I wrote Mini Aquariums (TFH Publications, 2008), but my research for that book really fueled the fire. In my presentations I discussed a concept I developed for the book: the mega nano, or using large tanks to house very small fishes. There are many natural behaviors that can be observed in a mega nano that aren’t normally seen in an aquarium. Many gorgeous planted tanks wind up being mega nanos, not because they set out to be, but because a light bioload is excellent for the aquascapes. Thus, aquatic gardeners often get to see their fish’s act as they would in the wild as a bonus to the beauty of the plants.

The audiences seemed to enjoy my talks and offered many personal experiences in response to my ideas. I found both clubs to be vibrant and exciting, with far-reaching interests and the type of camaraderie and helpfulness that seem to be universal features in aquarium societies. Although it’s never enough, there was some time for casual conversations with the members, fish room visits, and trips to a few LFSs.

A special thanks to the members of both clubs for their warm welcome and to Ted and Deb Judy and their sons Thomas and Matthew, my gracious hosts.

Posted September 21st, 2011.

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Hurricane Help

Keeping your aquatic pets safe is an important consideration in an emergency. Photograph by Tony Terceira.

By David E. Boruchowitz

With a major hurricane bearing down on the heavily populated Northeast, the obvious priority is to ensure the safety and well-being of family, friends, and neighbors. Once that is done, aquarium keepers will undoubtedly want to ensure that their pets will weather the storm in good shape.

Since this is a summer storm, the loss of heat is not a major worry, but the loss of electrical power, particularly for an extended time, is the most significant concern. A backup generator is the best preparation, but that’s not much of an option for people in Irene’s path at this time. So what should you do?

  • Stop feeding your fish. While this may seem unrelated, it could easily make the difference of survival for your tanks. When your fish are fasting, they present less of a bioload, one more likely to be handled by a diminished biofiltration capacity.
  • If the stocking in your tanks is quite variable, you might want to move fish from more heavily stocked setups to less heavily stocked ones to even out the load.
  • Make provisions for supplemental aeration. This can include battery powered air pumps but can also be as simple as regularly and vigorously stirring the water surface of an aquarium. Scooping some of the tank water into a pitcher or bucket and pouring it back in from a height will also effectively aerate the water.
  • If the power goes out and stays out, unplug and disconnect canister filters. You may want to open them and remove the media, keeping it moist to maximize the survival of aerobic bacteria. During the outage sealed chambers will become anaerobic, and toxins produced by the bacteria that live in anaerobic water must not be flushed into the tank when the power resumes. Instead, clean and purge the filters before starting them up again.
  • Plan for careful monitoring after the crisis passes so that the die-off in biofilters does not result in ammonia or nitrite spikes. Be prepared to do plenty of water changes as your biofilters return to full potential.
  • (Reefkeepers face special challenges, but unfortunately the only way to deal with many of them is to have already installed a backup generator.)

We at TFH hope that all of our readers in the path of this storm, however it tracks, will suffer no serious harm or loss, and that their setups will continue to thrive. Please, be safe!

Posted August 26th, 2011.


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