That Fish Blog – Aquarium Advice and Information

Although goldfish made their debut as pets over 2,000 years ago, their needs are not always understood by those new to fish-keeping.  Because the average pet store goldfish is small and inexpensive, they are sometimes viewed as “beginner’s pets” that need little care.  Add to this the fact that many people remember “Grandma’s goldfish that lived for years in a tiny bowl”, and it’s easy to see why most meet untimely ends (well-cared for goldfishes can live into their 20’s – and sometimes to twice that age!).  Folks who buy a single goldfish usually do not want to be bothered with a filter, but the lack of filtration is by far the main reason for failure with these otherwise hardy fishes.  However, there is a filter that needs no pad or carbon changes, and which becomes more effective with age – custom made for busy, “filter-shy” fish enthusiasts.  Today we’ll take a look at it and other simple options that will lessen your workload and improve your goldfish’s quality of life.

 

Goldfish Do Not Stay Small!

When considering a goldfish, it’s important to realize the potential size your pet will reach.  Goldfish are available in a wide variety of colors, 4 tail-shapes, 3 body-shapes and 3 eye-types, but are all of the same species, Carassius auratus auratus.  Those known as comets – the basic pet store or “non-fancy” goldfish – can easily reach 8-12 inches in length.  Sixteen-inch long individuals have been recorded; in fact, I have seen several feral goldfishes near that size in the Bronx River, mixed in with breeding aggregations of carp (I must check if hybridization is possible…).  Fantails, moors and other strains tend to be shorter in length than comets, but they get quite hefty.

 

True, improperly-kept goldfishes will become stunted, and may survive in that state for several years, but this is not to be encouraged – and certainly not a lesson to be teaching the children for whom single goldfishes are often purchased.  When fully-grown, your pet will need a 20 gallon aquarium in which to live; plan on a 30 gallon for a pair.

 

The Ultimate Goldfish Filter

Although now largely-ignored by hobbyists, (perhaps they are “too simple”!), undergravel filters were once considered indispensable by serious aquarists, and are still relied-upon by many public aquariums today.  In zoos and at home, I’ve used these highly-effective filters in aquariums housing creatures ranging from seahorses to alligator snapping turtles, always with great results.

 

When considering undergravel filters, it’s important to bear in mind that biological filtration – the breakdown (by aerobic bacteria) of ammonia to nitrites and nitrates – is the most important function of a filter (please see article below).  And it is at this aspect of filtration that undergravels excel.  Simply-put, an undergravel filter turns your aquarium’s substrate into a giant, living, biological filtration unit.  What’s more, the filter plate does not take up important living space and, being hidden below the gravel, allows for the creation of pleasing aquascapes.  Best of all, there are no cartridges or filter mediums to clean or replace! 

 

Water Changes

Regular partial water changes are essential to maintaining water quality and fish health…regardless of tank size, filtration method, or fish species.  When doing partial water changes, be sure to use a manual or battery-operated gravel washer.  In this way, you will remove debris trapped in the substrate along with the water…that’s all the maintenance your undergravel filter will need!

 

Currents

Undergravel filters have another characteristic that suits them well for use with goldfish.  Goldfish evolved in slow-moving waters, and they cannot abide fast currents; fantails, lionheads and other round-bellied varieties are especially-weak swimmers.  Yet they produce a good deal of waste, and do best in aquariums equipped with powerful filters (which usually put out strong outflow currents).  Undergravel filters discharge clean water through two tubes that reach to the water’s surface…even when very powerful air pumps are used, outflow currents remain mild.  You can check out a wide variety of air pump styles and sizes here; please post below if you need assistance in choosing a pump.

 

Increasing Your Filter’s Efficiency

Power heads can be used in place of air pumps if you need to increase water flow through the gravel bed.  You can also set up a reverse-flow system, which will lessen the amount of detritus that becomes trapped in the substrate; please post below for details.

 

Commercially-available aerobic bacteria (i.e. Nutrafin Cycle) can be used to jump-start your filter or to boost the beneficial bacteria populations that have developed naturally.

 

Other Goldfish Filters

From simple corner filters to state-of-the art canisters, there is a huge array of other filtering options for goldfish owners.  Please share your thoughts and experiences by posting below.

Further Reading

Aquarium Filtration: Understanding the Nitrogen Cycle

Making the Most of Undergravel Filters

With the wide range of body shapes and colors, it is hard to believe that all of the fish we call “goldfish” come from the same ancestor, a rather dull, silver/brown carp known as Carassius auratus. Almost two thousand years ago, Asian fisherman raised these fish in ponds for food, and soon the natural orange and yellow mutations of these fish caught the eye of Chinese royalty. Over time, the fish that we know as “goldfish” were selectively bred for specific traits and colors which would eventually become the varieties we see in fish stores today. Let me introduce you to some of the most popular “breeds” that have become aquarium mainstays over the past few hundred years.

Made for Outdoor Living

Comets – Perhaps the closest in appearance to the “natural” carp, Comets have longer fins than the common goldfish, and are often sold as “feeder fish”. They can be orange, white, silver, yellow or black. They get fairly large and are often sold for ponds rather than aquariums. The Sarasa Comet is a very popular variety whose coloration is a combination of pure white and deep red. Read More »

GloFish are some of the most popular, colorful and controversial fish to enter the aquarium trade in a long time. Their easy care, small size, peaceful nature and neon bright colors make them appealing to aquarists of all ages, but the modifications that cause these bright colors cause some debate among aquarists, scientists and environmentalists alike.

The original “GloFish” were not created for the aquarium trade. They came from a popular fish used in many different fields of research, the Zebra Danio (Danio rerio). Zebra Danios have been used in research for environmental studies, cancer research, genetics, reproductive biology, neuroscience and applications to other fields as well. They even made the trip to space in 1975 on the Russian “Salyut 5” space station. So what makes them such good research subject? Zebra Danios are easy to breed and it only takes hours for the internal organs to develop after the eggs have been fertilized (about 24-36 hours, depending on temperatures and conditions). During this time, it is easy for researchers to monitor the development of the embryo since the “shell” around the eggs is a clear membrane. The eggs can hatch about 12-36 hours after that (again, depending on the conditions). These variable time frames also mean that, while the development is being studied, conditions can be adjusted to slow down or speed up the development, depending on what exactly the researchers are trying to determine. The genetic sequence involving the structure of the Zebra Danio’s DNA and RNA is very well-known at this point and is comparable enough to our own that, by understanding how changes in this structure affect the fish, researchers are gaining more understanding into how changes in our genetic structure can affect our own health.

Originally, GloFish were being developed for two major fields: cancer research and pollution detection. In the late 1990’s/early 2000’s, researchers thought to develop a fish that would change colors when a certain pollutant was found in their water. The thought was to develop a fish that would appear normal in “ideal” conditions but when a specific chemical or type of chemical was present in the water, a “trigger” would be set off to cause the fish to “glow” with a fluorescent protein in their bodies. As a step in this direction, they began to develop a fish that would always have this flourescent “glow” in a reproducible and hereditary way that wouldn’t affect the ecosystem around them. To do this, scientists turned to a fluorescent protein naturally found in jellyfish, corals and anemones rather than potentially harmful chemical dyes. Around the same time, similar projects were using a fluorescent protein to “mark” specific genes that were thought to be a cause or sign of cancer. By pairing the fluorescent protein with the cancer-related gene, researchers could see the fluorescence increase or decrease along with the other gene and see if an increase or decrease in that gene was related to the cancer. Since the genes (and cancers) in these fish behave in much the same was as they do within ourselves, researchers are using this to develop a way to track, diagnose and treat cancer in people. Read More »

Maintaining proper aquarium temperatures is essential for the health and well-being of your fish. While aquarium heaters do a pretty good job at this, the probability of fluctuations from fall through spring tends to be greater and possibly more detrimental. You may not even realize how much the temperature of the water changes through the day or day-to-day until you’re faced with ich or some other problem in your aquarium.

The Threat of Cool Temperatures

While our aquarium fish will rarely if ever be exposed to near or below freezing temperatures in the safety of your home (hopefully), fish farmers in Florida can attest to the immediate and lingering problems that can come with even short exposure to cold temps. Exposure to temps below 60 F can create chaos in a tropical tank, so you can imagine what freezing temps do to tropical fish housed in an outdoor setting. Sensitive fish may be killed outright from the shock of extreme temperatures or fluctuations in temperatures. Others face blows to their immune systems and the increased chance of being infected by opportunistic parasites, fungi or bacteria. These organisms take advantage at the slightest sign of stress on the part of tropical fish, and can decimate the population in a short amount of time. Cooler temperatures tend to make normally active fish lethargic and slower to react, making them more open to predation if outdoors. Similar problems can occur in the aquarium if smaller or more sensitive fish are not able to hide or escape the curiosity of larger, hardier tankmates.  Read More »

Hi, Dave again. This past week I attended the annual Global Pet Expo in Orlando. Global is the biggest pet trade show in the U.S., where many vendors show of their new products for the year, as well as show off some prototypes for thing to come down the road.
When you think of new products, fish don’t exactly jump to mind, after all we don’t make fish…or do we? Captive bred fish have been the driving force in freshwater aquariums for many years, with many manmade fish on the market, freshwater and saltwater. Fish like the many types Fancy Goldfish, Bloody Parrots, Flowerhorns and more recently the bioengineered “Glo Fish” are common to the freshwater aquarium hobby. Selective breeding and hybridization have resulted in many manmade fish over the years. Read More »