Shelter dogs aren’t the type to lie low and watch the world of human feet go by visiting hours are the time to show off how loud you can bark and how high you can jump. But in just a few minutes, you can have your bouncy dogs on their bellies in no time. More than just an amazing trick, the “down” exercise is a quick and easy source of mental stimulation for dogsand a great way to show adopters how trainable your animals really are. Shelter dogs who know how to respond to the flick of a wrist also have a hip edge over their counterparts in pet stores.

1. Good Eats Make Attentive Students
First, choose an eager canine student who is relatively at ease in the shelter; this method is most appropriate for happy, stable dogs whose social skills need just a bit of refining. Take your new friend to a venue that’s a bit less distracting than the kennels: an office or dog-walking area will do. (You can even incorporate this mini-session into doggie potty breaks.) Have a handful of tasty treats at the readythe way to a canine’s mind is often through his tummy.

2. Practice Doggie Sign Language Start the dog in the “sit” position. Kneel or squat so you’re closer to whisker level. Now employ the hand signal by flashing your right hand in front of the dog’s eyes, with your palm toward the dog and your fingers together; at the same time, lower your left, treat-filled hand and place it between his paws.

Hold the treats in place while you quickly move your right hand to your little buddy’s shoulders; rest your hand there gently. Do not force or push the dog down; your hand signal simply goes along for the ride to keep him from standing.

Ifhe does happen to spring up, just start him again in the “sit” position and repeat the above steps. As soon as his elbows touch the ground, reward him instantly so he learns to associate food with lying flat on his tummy. If he gets excited, he may pop back up; in this case, just stop feeding so he can distinguish between behaviors worthy of treats and those that are a little less desirable.

3. He’s DownBut Not Out
Repeat the exercises above until your precocious student is plopping down on a dime. To teach your friend how to stay down, release him with a quiet “okay” before he gets up, but don’t say anything once he is up and moving around. Praising and feeding him while he’s down will ensure that he gets the message about what you want him to do.

4. How Low Can He Go?
Now it’s time to test your poochy protg’s ability to apply what he’s learned. Start by luring him to the down position with your hand signal in the air and some treats near his toes. Instead of giving him a treat, release him from the position with an “okay.” Lure him down again, this time rewarding him with a treat when he comes in for a landing. Once he’s accomplished this step, he’s ready for a more advanced examination: Hold the treats in your left hand, but keep that hand in front of his nose rather than on the floor. Don’t lure this time; just give the dog the hand signal, and keep your hand suspended there as you watch the wheels start turning.

5. Behold the Touchdown
Allow the dog some time to make the connection between behavior and treats. If your friend starts looking confused, moving his gaze from the treats to your hand and back to the treats again, don’t worry. Be patient; this may be the first time in his life that he’s been encouraged to use his brain, so give him time to figure out the correlations. Just when you think you’ve all but lost him, he’ll plop that little tummy down with gusto. Reward the little guy immediately, allowing him to nibble from your jackpot of treats. If he doesn’t go down, don’t worry; just repeat steps 1 and 2, and test again.

6. Rise and Shine Once the dog has mastered his new trick, elevate his knowledge a bit by teaching him to understand the “down” signal when it’s delivered a few feet above his head. First, while you’re still kneeling, hold the treats near your waist with one hand while giving the hand signal with the other hand. Give the dog a treat as soon as he’s down. Now stand up, still holding the treats, and see if the dog understands your hand signal from higher ground. Sometimes munchkin dogs who are low to the ground have a harder time with this, so if yours doesn’t respond immediately, don’t worry. Just crouch down halfway and gradually work your way up to a standing position. Soon enough, the hand signal will become second nature to your little buddyand he’ll be sinking to new and wonderful lows every time an employee, volunteer, or potential adopter flashes a palm at him.

Are you thinking of getting a new bird as a pet? Each species is unique and wonderful in its own way but there are some general guidelines that apply to them all.

Be sure the bird you choose is healthy. A sick bird is no bargain no matter what the price. By the time a bird shows any symptoms of disease, illness has usually become quite advanced. If a bird appears droopy, ruffled, tired or hides his head under his wing, this is not the bird for you. If he sneezes, sits on the bottom of the cage, has a discharge above his nostrils or droppings stuck to his tail feathers, there may be big problems. If he makes clicking sounds as he breathes or if his tail bobs, the bird may have serious respiratory disease and you should choose another individual.

Signs of good health in a bird include bright eyes, clean shiny feathers, good appetite and lots of energy. Healthy birds eat often and are active. To help insure a healthy pet, obtain your bird from a reputable bird store or breeder.

Take your new bird to an avian veterinarian for a "well bird check up" immediately. Good pet stores will allow you to return a sick bird. This insures that you get a healthy pet, and lets you meet an avian veterinarian in your area. It also helps the pet store or breeder maintain healthy birds.

During your bird's check up, the avian vet can advise you as to diet, maintenance, training, hygiene and medical needs. Be wary of any pet store that claims the bird needs no medical attention. It is important for ALL birds to have routine check ups, one when newly purchased and then every year for healthy birds.

Now, how about setting up your bird's new home? You want it to be safe and comfortable. Buy the largest cage you can reasonably manage in your home. Be sure he can not slip his head between the bars. It should be convenient to clean and allow easy access to food and water containers. The perches should be of varying sizes, preferably of natural branches. These can be purchased at pet stores or you can collect your own. Manzanita, madrona and eucalyptus are all safe woods for birds to chew. Rinse them off before placing them in the cage. If you have other birds, place your new bird in an isolated room since many birds harbor contagious, disease causing organisms. This is very important to the well being of all of your feathered pets. The avian vet can advise you as to the safety of introducing him to your other birds when you have the exam.

Bird's diets vary greatly from one species to another, but a good rule is that no more than 50% of a bird's diet should be seed and nuts. The remaining 50% should be vegetables, leafy greens, fruits, small amount of cheese, lean cooked meats, boiled egg and other "people foods" with a powdered vitamin supplement added. Many birds love yogurt. All need fresh water daily.

Avoid walnut shell bedding material for the cage bottom. This frequently carries a fungal infection called aspergillus. Paper towel or corn cob bedding is all fine. Clean or replace them daily.

Finding an avian veterinarian can be difficult. Many vets do not treat birds, so it is important to find a specialist in avian care. Sometimes the breeder or pet store where you purchased your bird will have a referral to a local avian practitioner. If you are having a difficulty finding one, call your local Veterinary Medical Association for a referral.


Nutrition

What does your bird need? We now know that seed is not the only food needed by pet birds, and in fact, birds on a seed only diet, are very unhealthy. Only 50% of a bird's diet should be seed. Of the other 50%, fruits and vegetables are the most important. This is where he obtains vital minerals and vitamins. If your bird is reluctant to try new foods, try cutting the fruits and vegies into small, seed size pieces. Sometimes mixing them into the seed helps. It is all right to cut back on his seed a bit. "Hunger is the best sauce" as they say. It is also okay to remove his seed for most of the day, offering it only for an hour in the morning, and an hour in the evening. During the day he will have only fruits and vegies to eat. If he is a little hungry, he will try new foods.

Out in the wild, birds eat a wide variety of nuts, small pieces of meat, even another bird's eggs occasionally. So how do we duplicate this variety? A good rule of thumb is, if a food is healthy for a human, it is healthy for your bird. Birds enjoy spaghetti or a bit of chicken. Hard boiled egg is often a big hit. Almonds, walnuts or other nuts are fine in small quantities. Many birds love cheeses and yogurt. Monkey chow is a tasty treat and an excellent source of protein for birds. It is available at most pet stores. Cuttlebone and mineral blocks are a good source of calcium. If you have any questions about whether a food is good for your bird, call your avian vet for more information.

To make sure he's getting everything he needs, supply fresh water. Some species, such as cockatiels and budgies, drink very little water and may benefit from a powdered vitamin sprinkled on moist food.


Pet Bird Safety

Those of us who have raised puppies and kittens know how dangerous a house can be. Mischievous, exploring young pets seem to find every available risky item in the first 24 hours of arrival. Having learned too dog- and cat-proof a house, we may feel prepared to safely welcome a pet bird into our lives. There are surprises in store. Birds add a whole new dimension to pet safety worries.

Unlike dogs and cats, birds fly. Birds fly into windows or mirrors, injuring themselves in the process. Decals or curtains allow a flying bird to see them and avoid a crash. Birds fly out of windows, never to be seen again. Screens are essential for windows and doors. When a bird is out of its cage, always remain nearby.

Even a bird with properly clipped wing feathers can flutter to disaster around the house. A ceiling fan should be an obvious "no-no," but other mechanical appliances can be equally dangerous. Birds have been injured falling into electric beaters in the kitchen. They can fly and land on hot surfaces or into scalding water. Expect the unexpected with birds. If you open the hot oven, your parrot may pop right in!

If your bird is always confined to its cage, some of these precautions may seem excessive. Remember, escape is always possible, and accidents do happen. Besides, an owner of a well-trained bird will want to spend lots of quality time with the bird at this or her side (or shoulder). Most birds thrive on attention and human interaction, but wither with neglect. Plan for avian safety in all the rooms of your home.

Birds are exquisitely sensitive to toxins, especially those in the air they breathe. Remember about the canary in the mine shaft giving warning of gas accumulation? Cleaners, such as those used to degrease ovens, produce dangerous airborne contaminants and can be fatal to birds. Even strong cooking odors and smoke is a risk. Non-stick cookware is another worry. When overheated, the fumes can kill birds.

Birds can drown in small amounts of water. Upright narrow glasses are a danger as is very hot water (birds don't expect the water to be hot). The toilet bowl, uncovered, has been the source of many avian injuries. Birds do like water play, and with supervision, many even enjoy showers with their owners. Bath perfumes and hair spray must be avoided around birds.

Chewing is the next big concern with birds. Most birds chew anything they can get their beaks on. We must provide safe woods and chew toys to allow this natural, healthy exercise. It is also essential to keep the house clear of dangerous items. Anything made of lead is forbidden (fishing weights, stained glass, metal toys, costume jewelry). Electric cords should be hidden and protected. Avoid poisonous house plants.

As you get in the habit of thinking about kinds of things that poison birds, you will automatically avoid the dangers. Remember, things that smell strong to us can often kill birds. Felt tip pens are aromatic and poisonous to birds. Nail polish and remover, paint fumes, cigarette smoke, colored ink and aerosol sprays of all kinds should be avoided. Other pets, such as cats, must be kept safely away.

There are many items to remember and dangers to avoid in keeping your pet birds safe around the house. Prevention, however, is always preferable to emergency medical intervention! Keep the name and number of your trusted avian vet handy just in case.


Knowing When Your Bird is Sick

Birds who die "suddenly" have usually been sick and no one knew it. But take heart, there are some good indicators of poor health. You only have to know what to look for. Once you learn the signs of early illness, needed treatments can be performed by your avian veterinarian.

Some of the best indicators of health is the bird's droppings. The droppings are made up of feces, normally black or dark green. With this will be urine, which is clear, and urates, a creamy white waste material. Droppings with a mustard yellow liquid portion is not normal, nor is blood or rusty brown color in feces. Healthy birds eat often and make lots of droppings. A sick bird may have fewer droppings, or no fecal portion in them, just white and liquid.

Another indicator of illness is change in eating and drinking habits, for example, excessive water consumption. A bird who isn't interested in food indefinitely is ill. A change in attitude or behavior can signal illness. Has he stopped talking, or does he appear sleepy and lethargic? Is he huddled on the bottom of the cage or sitting low and ruffled? Is he hiding his head under his wing? How about his feathers? Are they dull? Has he stopped preening himself? How about weight loss? Any of these symptoms indicates potentially serious problems.

Another sure sign of illness is any hint of respiratory distress. Open mouth breathing or any audible sounds, like clicking or wheezing are certain problems. A tail bob is actually a sign of respiratory distress! Vomiting in birds is very abnormal unless it is regurgitating to feed a mate or baby. Any discharge from the eyes or nostrils is a sign of illness, as is a swelling around the eyes. Of course, any injury or bleeding requires immediate veterinary care. A broken "blood feather" must be pulled immediately to stop the bleeding. These new, immature feathers are recognized by their protective "cellophane-like" wrap and their visible blood supply.

If your bird displays any of these signs, take the bird to your avian vet. Meanwhile, keep the bird warm: 85 degrees is ideal with access to a cooler area. An ordinary heating pad wrapped around on the side of the cage is fine. Offer food and water, placing it on the cage bottom if the bird is weak. Never give your own medicines, antibiotics or pet store cures to your bird. These can do more harm then good. Your avian vet will prescribe appropriate and SAFE medications.


Trimming Wings, Beaks and Toe Nails

Any bird in your home needs his wings trimmed unless he is an aviary bird. Concussions often occur when birds fly into windows or mirrors. Serious burns result from birds flopping into pots over stove flames. Many beloved birds fly out open windows or doors and are never seen again!

Wing trims can be performed at home, or you may choose to have your avian vet do it. It is best to watch an experienced person perform a wing trim before doing it yourself. Never cut a "blood feather." This is a new feather still in its sheath. It has a prominent blood supply and will bleed if cut or broken. If you accidentally cut one, the only to stop the bleeding is to grasp the wing and pull the feather out at the base. The best wing trims allow the bird to flutter to the ground but not maintain flight. This is accomplished by cutting feathers of both wings. Once a wing trim has been done, hold your bird close to the ground, allowing him to gradually discover that he can not fly.

Some birds' beaks may never need trimming, but others have overgrown tips or cracks that need smoothing. The beak has a blood and nerve supply and it is a good idea to let your avian bet decide how much, if any, should be removed. Most vets have a special tiny sanding tool to use. This is not recommended at home. Birds with "scissor beak," a mal-alignment of the upper and lower beak structures, can be helped by routine trims and shaping.

Nail trimming is the most common avian grooming procedure. This can be done at home, but again it is advisable to learn from an expert. The nails will bleed during a nail trim, and a styptic powder such as "Quik-stop" will stop the bleeding. Parrots may have nails that become very sharp and painful to the person on whose shoulder they are perched. Do not give your bird sandpaper perches in hopes of wearing the nails down. These perches cause serious foot problems, including chronic ulcerated sores, and do little for the nails.

                                                                               Introduction to Aquariums

Keeping an aquarium can provide immeasurable rewards and satisfaction. It does, however, require some work as well, and before you venture into the hobby, you'll need some fundamental information.

The best way to begin is with a basic understanding of what happens in a successful aquarium. You'll also need to know how to select a good aquarium store, one that can provide you with reliable equipment, service, and advice.

Finally, you'll need to take the first step in planning your aquarium: selecting a tank and a suitable location for it.
                                                                                   The Closed Aquatic Environment

It's actually amazing that fish can survive in an aquarium at all. Compared with their natural habitats -- from jungle streams to vast lakes -- even a relatively large aquarium is tiny.

An aquarium also has several built-in limitations that work against the health of its occupants. No matter how extravagant and no matter how carefully planned, any aquarium is an artificial environment.

Natural aquatic ecosystems are much more complicated than the aquatic environment of an aquarium. The biological processes in a body of water have been finely tuned over millennia to become a complex, living system.

This system includes weather patterns, geological and chemical processes, and countless interrelationships among plants, animals, and microorganisms. The lifeforms found in these systems have adapted to very specific conditions, and their ability to survive depends on their environment.

A closed system like an aquarium is a completely different thing. By definition, a closed system means that the environment consists solely of the tank and its contents. The natural processes that, in the wild, would provide food, protection, and a clean, uncontaminated environment for the fish are not a part of the aquarium.

As a fishkeeper, your primary responsibility is to see that these things are taken care of in the confines of your aquarium.

Providing nourishment and a safe and comfortable habitat are essential. Maintaining the water quality, however, is something a bit less obvious to most new aquarists.

Water quality refers to the amount of debris, pollutants, and other undesirable substances that appear in the water either naturally or through contamination, and more aquariums fail due to poor water quality than probably anything else.

Why is water quality so important? Approximately 80 to 90 percent of all fish diseases are due to physical stress. The most common source of stress is from living in polluted water.

This stress, if persistent and unrelieved, causes the immune system of a fish to become less and less able to fight infection from disease-causing organisms that are always present in the water. Some species of fish suffer from this problem more quickly than others, but all fish eventually become sick and die when kept in poor-quality water.

Beginning aquarists may have a difficult time keeping their aquariums healthy not because they lack skill or motivation but because they lack knowledge. Keeping water clean is actually not difficult at all; it requires only a little understanding, a little effort, and the right equipment.

                                                                                    Aquarium Water Quality

Aquarium water quality deteriorates for several reasons. As a part of their metabolism, fish produce various waste products that accumulate in the water, and other organic matter such as uneaten food decays into substances that can contaminate the water.

Over time, these pollutants build up in an aquarium to a level that is dangerous to the occupants. In their native environment, fish are protected from this problem by a natural system. The water in a river or lake is continually replenished with fresh rainwater, and different chemical and biological processes remove organic pollutants from the water.

To keep a healthy aquarium, you simply need to understand this natural system and duplicate its effects for your fish.

Prior to the advent of filtration, hobbyists depended on their ability to maintain a balance in the tank. The number and size of fish, the abundance of plants, and the ability of snails and other scavengers to consume excess food and other materials in the tank were all taken into consideration.

It was, however, a balancing act that only the most skilled aquarists could maintain over time. The number of fish that could be kept in these balanced or natural aquariums was rather small. And yet, when measured against the natural environment of the fish, even these aquariums were rather overcrowded.

Today, new hobbyists often believe that aquarium technology, particularly the filtration system, eliminates the work and the problems of keeping fish. Up to a point, this is true.

Certainly in comparison to keeping fish in a bowl, where all of the water must be changed at least once a week, an aquarium with a filter is more convenient and easier to maintain. Still, filtration systems have limitations.

No matter how sophisticated, a filter can only slow down the rate at which the water in an aquarium becomes polluted. No filter system can actually stop water quality from deteriorating. Filtration is important to maintaining good water quality for the fish, and filters do make it possible to keep more fish in an aquarium.

Success with fishkeeping, however, requires more than a good filter. The true value of filtration is that it helps you maintain good water quality more consistently, but only if some easy-to-follow principles of aquarium care are followed.

The real key to success is found in three basic rules, each formulated to create a stable environment for the fish. Rule one is to not overstock the tank with fish. The more fish there are in an aquarium, the faster the water quality goes down. As noted earlier, the filter only slows this process.

The second rule is to not overfeed the fish. The accumulation of uneaten food in the tank will quickly contaminate the water. Rule three is to do frequent partial water changes. This removes pollutants and adds fresh, clean water to the aquarium, helping to maintain a healthy habitat.

If you understand these three rules and the reasoning behind them, you're well on your way to becoming a successful aquarist.

What remains is to learn about the equipment you'll be using -- what you need and why you need it -- and then to learn a little about the fish that you'll be setting up house for.

                                                                                    Where to Shop for Aquariums


New hobbyists seldom realize how valuable a good pet store is to their success in fishkeeping. Value, in this case, has nothing to do with the lowest prices or shortest driving distance.

When determining where to shop for aquariums, what you want is a store that can offer good advice, provide solutions to problems, recommend products that will best serve your needs, and handle warranties or repairs for equipment.

If you live in an urban area, you probably have dozens of pet and aquarium stores to choose from. The smaller the city or the more rural your area is, the fewer shops there will be.

One of your first goals is to visit as many aquarium dealers as are convenient before you purchase anything. As you visit each store, there are certain things to look for. The shop should have a clean appearance. The floors should be swept and the carpets vacuumed.

Shelves should be stocked with a variety of merchandise. Dust, particularly on containers of food, means a low turnover of goods, increasing the likelihood of old or outdated products.

The tanks themselves should look well kept. The water should be clear and the front glass clean -- no water spots on the outside or algae on the inside. The tanks should be clearly labeled with the names and prices of the fish contained within them.

The fish should be healthy and active; that is, individual fish should display color and behavior that is typical of the species. In a large store with many tanks, the occasional dead fish in a tank can happen. However, if many of the tanks contain dead fish, or if the employees seem uninterested when a dead fish is pointed out to them, you'll want to take your business elsewhere.

If the fish aren't healthy when you buy them, they are unlikely to become healthy in your own aquarium, and they could be carrying disease that will affect your other fish.

Note whether the dealer has a good selection of nice-looking live plants. Even if you end up using artificial plants, a store that stocks specialty items like good-quality live plants is much more likely to serve the needs of hobbyists at all levels.

Also look for a display of aquarium books. A large and varied number of titles indicates a dealer who knows how important reading about the hobby is for aquarists -- particularly beginners.

The quality of the sales staff is also important. They should be knowledgeable about the hobby in general and interested in your questions. They don't have to know the answer to every question, but they should be willing to find out what the answers are.

Do not simply patronize the shop with the lowest prices. As often as not, the shop with the lowest prices has the least knowledgeable staff, the poorest selection of merchandise, and the least healthy fish. It is always better to pay a little more to a reliable dealer who will support you and help you grow in the hobby.

After you've purchased your aquarium, you'll want to put it in the most optimal spot in your home.

                                                                                     Choosing an Aquarium Location

There are three basic factors to consider before actually purchasing an aquarium. You want to decide where the tank should go, what kind of fish you want to keep in it, and how much money you feel comfortable spending. You should really make these decisions before bringing home a tank. Aquariums last for many years, and if you make the wrong choice, you may have to live with it for a long time.

The first thing on the list is choosing an aquarium location. It is important that you be able to view the aquarium easily from a favorite chair. Keeping the tank in an area where you spend a lot of your time will enhance your enjoyment of your fish and your interest in fishkeeping.

Sitting comfortably and watching the fish lets you appreciate them, and it also provides an opportunity to note if they are behaving normally. Experienced aquarists can catch problems early by simply noting changes in the behavior of their fish.

The tank also has to be in a place that offers ready access. Although an aquarium doesn't require much maintenance, it does need some. If it is difficult to work around the tank because of a lack of space, you will be much more likely to put the work off and let the water quality deteriorate, and as a result, keeping your aquarium healthy will become much more of a chore.

The location of the tank should also be determined by the room's light, temperature, and traffic. One of your goals is to provide the fish with a stable, secure environment. This is much easier to do if you can control these factors.

Sunlight coming through a window or door can overheat the tank, particularly in summer, raising the water to lethal temperatures. Excess light can also cause significant algae growth in an aquarium. The combination of warm water, sunlight, and nutrients in the water encourages unwanted algae to multiply and cover every surface in the aquarium.

Nearby windows and doors can subject the tank to drafts of cold or hot air, making it harder to maintain a consistent water temperature. Rapid changes in temperature create enough stress to cause some fish to become sick. For this reason, the tank should also be kept away from radiators, vents, and other sources of hot or cold air.

Heavy traffic around the aquarium can be very disturbing to many fish. If people are continually walking by the tank or if nearby shelves or furniture receive frequent use, the activity can stress the fish and make it more difficult for them to thrive.
                                                                                     Choosing an Aquarium Display

In addition to picking the location, you must take time when choosing an aquarium display. The tank must sit on a sturdy support. A table or other piece of furniture is seldom suitable except for the smallest of tanks.

The weight of a typical aquarium is roughly 10 pounds per gallon, so a 10-gallon tank will weight about 100 pounds and a 30-gallon tank will weigh about 300 pounds. Most furniture is not designed to support that kind of weight. The furniture would also suffer from the effects of spilled and splashed water, which is a virtual certainty no matter how careful you are.

For these reasons, the best way to support an aquarium is with a stand designed specifically for this purpose. These are usually made from wood or wrought iron, sometimes with a second shelf for another aquarium or for supplies and equipment.

Even better are stands with doors to hide air pumps, filters, food, and other items. If you are willing to spend the money, custom-crafted aquarium furniture can make the aquarium fit perfectly into the decor of any room.

The floor itself must be level and capable of withstanding the total weight of the aquarium and support. The main reason for needing a level floor is to avoid uneven stresses on the tank that might cause a leak. It also looks better if the water line is even at the top of the tank. With most tanks, weight will not be a problem.

However, for very large aquariums, 100 gallons or more, some floors may have to be reinforced. One problem with most stands is that all of the weight is actually transmitted to the floor at only four points, where the legs are. It may help to distribute the weight more evenly by placing lengths of wood under the legs.

                                                                                     Choosing Aquarium Dimensions

Your next concern is choosing aquarium dimensions, which includes both the size and shape of the aquarium.

Ideally, you want to purchase the largest tank possible -- one that you can afford and that will fit into the chosen space. A larger aquarium will hold more fish, of course, but greater size will also provide a more stable aquatic environment.

As the volume of water increases, it can be easier to maintain consistent water temperatures and good water quality. This is not to imply, however, that a modest-size tank will have problems. With a little care and attention, any tank of 10 gallons or more can be a healthy home for fish.

The cost of an aquarium rises moderately with its size until you pass capacities of about 55 gallons, at which point prices rise much faster. The amount of glass needed for very large tanks and the increased thickness required as the tanks become deeper contribute to these price increases.

The numbers and sizes of fish that can be kept are affected by both the tank size and the tank dimensions. For this reason, it may help to know what kinds of fish you want to keep when shopping for an aquarium.

If you don't want to plan that far in advance, just be aware that you may have to avoid certain types of fish if your aquarium is not suitable for them. Don't worry, though; no matter what kind of tank you buy, you'll be able to choose from a great variety of potential residents.

You will discover that aquariums of similar or identical capacities can have very different dimensions. While the amount of water that an aquarium holds is important, many new hobbyists do not realize that the dimensions of a tank can be important, too.

The length and width of the tank determine the surface area of the water, and surface area directly affects the number and size of fish that can be kept in the aquarium. The significance of surface area may not be clear until you understand a little more about the biology of an aquatic environment.

One of the most important rules of successful fishkeeping is to not overstock your tank. Overcrowding can make it all but impossible to keep fish alive and healthy.

Increasing the filter size and the amount of maintenance can partially compensate for too many fish, but in the long run nature takes it course and fish will sicken and die until the aquarium is no longer overcrowded.

Exactly what constitutes overcrowding, however, is hard to say. Looking at the tanks in stores is no help because these aquariums are vastly overstocked. The short amount of time the fish are in these tanks, combined with extensive filtration and frequent maintenance, allows retailers to maintain heavy tank populations.
                                                      Choosing an Aquarium Size

For many years, aquarists have used guidelines that relate the size of the fish to the volume of the tank. The most common guide when choosing an aquarium size is one inch of fish per gallon of water. This refers to adult fish and does not include the tail.

Although not a bad rule of thumb, this guideline has two major shortcomings. First of all, a fish's length does not by itself indicate the total impact the fish will have on a closed aquatic system.

While some fish are slim, others have much fuller bodies. As fish grow, their weight or mass may increase much faster than their length. The end result is that an aquarium may meet the guidelines of an inch of fish for every gallon of water but still be overstocked or understocked.

The second problem with this guideline is that it doesn't account for surface area, which is a real limiting factor. Fish require oxygen to live. They remove dissolved oxygen from the water and release carbon dioxide into the water, so the dissolved oxygen content of a tank is one of the things that determines a safe stocking level.

Oxygen enters the water from the atmosphere at the surface, and carbon dioxide is released into the atmosphere at the surface. The greater the surface area, the greater the exchange of oxygen and carbon dioxide and the more fish the tank can support.

To take surface area into account, a good guideline for stocking an aquarium is one inch of adult fish (not including the tail) for every 24 square inches of surface area. This also does not account for the

difference between slim and broad fish, but this rule of thumb at least provides a greater margin of safety.

This guideline, by the way, is for tropical aquarium fish. Cold-water fish, such as goldfish, need 30 square inches of surface area per inch, which takes into account their much greater body mass per inch and greater oxygen requirements.

What all of this means is that when choosing an aquarium, it is best to try to select the one that has the greatest surface area for a given volume. If you choose a tank shape that offers less surface area, take that into consideration when stocking it.

Aquariums of the same capacity but different surface areas come in three basic types: regular tanks, show tanks, and long tanks. Show tanks tend to be taller than regular tanks, thus providing a larger front glass area to view the fish but a smaller surface area. They are narrower front to back than normal tanks.

Long tanks have a greater length than regular tanks, making for a very attractive display tank and increasing the surface area. Show tanks are particularly well-suited for deep-bodied fish, such as angelfish, whereas long tanks are good choices for territorial species or for fast-swimming, schooling fish.

A different tank shape is the hexagon aquarium, with six sides. These can make very attractive displays, but keep in mind that the surface area of this type of tank is less than that for a normal tank of the same volume.

Round or bubble tanks are even worse in this respect because the maximum amount of surface area is available only when the tank is half full. As the water level goes higher than this, the surface area decreases. This is the same problem that plagues goldfish bowls.

Worst of all are very tall, thin aquariums, which have the surface area of a much smaller aquarium.

Recently mini aquariums ranging from two to six gallons have become very popular. While they are attractive and inexpensive, these tanks can be very difficult to maintain. They hold limited amounts of water, they have only a minimal surface area, and they often come with inefficient filter systems.

Even experienced fishkeepers have a very difficult time maintaining healthy fish in tanks of this size.