Care Guide for Discus Fish – The King of the Aquarium

Discus fish are one of the most beautiful freshwater fish in the hobby, known for their spectacular colors and large, circular shape. However, they’re notorious for being extremely difficult to keep, with Internet forums often recommending strict practices like 100% water changes every day. In reality, only a small percentage of people are able to follow those rules, and the rest of the world uses more low maintenance methods. We’ve spent many years keeping discus personally at home, caring for them in our fish store, and helping customers be successful with them. Based on our experiences, this care guide offers practical advice and useful tips for beginners starting their first discus tank.

To read more on this story, click here: Care Guide for Discus Fish – The King of the Aquarium

Top 5 Benefits You'll Get From Owning Pet Koi

The Good and Bad of Keeping Koi

Any type of pet comes with their own challenges and setbacks, and koi fish are no different. They're subject to disease, emergencies and sometimes sadly turn out to be a bad fit for their owner. For the sake of those who have the time, finances and space to keep these great creatures, let's embrace the positive gems that koi have to offer.

1. The Best Parts of This Hobby

2. The Koi Pond Provides Moments of Peace

3. The Hobby Has a Great Social Factor

4. Keeping Koi Offers a Good Challenge

5. Koi Are a Reactive Pet

6. You Can Trade and Sell the Fry

To read more on this story, click here: Top 5 Benefits You'll Get From Owning Pet Koi

WHEN AND WHY TO STOP FEEDING YOUR KOI FISH IN WINTER

We’re moving into the winter season, and temperatures are dropping. You might be thinking about your koi pond and how your koi will fare during the winter months.

Your fish will be just fine, but colder weather does mean you need to adjust your feeding schedule.

Here’s how your koi feeding schedule will change as the temperature falls – even to the point where you stop feeding them until the spring.

HOW WEATHER AFFECTS FEEDING SCHEDULE

As the air temperature falls, your koi pond water temperature will drop. There’s a direct relationship between water temperature and koi feeding because your koi’s digestive system slows down as the temperature does (with one exception).

To read more on this story, click here: WHEN AND WHY TO STOP FEEDING YOUR KOI FISH IN WINTER

How To Raise Koi Fish In A Pond?

Koi fish are renowned as an easy-to-raised specie and if raising them successfully, you might earn a fortune from them.

However, there are still some certain requirements that you should keep in mind before bringing them home, such as pond sizes, expenses, living environments, and how to feed them. Rest assured, all will be told in this article.

To read more on this story, click here: How To Raise Koi Fish In A Pond?

'Massive' Goldfish Weighing 9 Pounds Found in South Carolina Lake

A goldfish weighing nine pounds came under the spotlight Monday after being discovered during a fish population survey at a lake in South Carolina, park officials said.

Ty Houck, an official with Greenville County Parks, said the “massive” fish was found swimming on Nov. 16 in a 12-acre body of water in Oak Grove Lake Park in the county of Greenville.

Greenville Rec, which oversees the park where the fish was discovered, posted a photo of the golden spectacle on Facebook on Monday.

To read more on this story, click here: 'Massive' Goldfish Weighing 9 Pounds Found in South Carolina Lake 

Koi Story: A Beginner’s Guide To Raising Koi Fish

Congratulations! You're made the most excellent decision to start raising koi fish of your own. Although it can be a little daunting at first to take on a new pet, you'll soon discover how easy it is to raise these hearty fish. Koi Story has put together this little guide to jump-start your knowledge on your fish pond/habitat, koi care and other general koi  knowledge.

RAISING KOI FISH IN A POND

Koi are a hearty member of the carp fish family and can handle quite a bit if the conditions of your koi carp pond are right. Seasonal ponds should be at least a 1.5 deep (half a meter) while year-long ponds should be at least 4.5 feet (1.5 meters). Water should be kept between 60 and 75 degrees F (about 15-25 degrees C)

Beyond depth and temperature, your koi/carp/fish need a few important things in a pond habitat:

To read more on this story, click here: Koi Story: A Beginner’s Guide To Raising Koi Fish 

Goldfish Survive 4 Months After New Zealand Earthquake

Two goldfish were found alive in their tank in a building that was badly damaged by the earthquake that struck New Zealand.

The two goldfish, named Shaggy and Daphne, have become the smallest survivors of the earthquake in February.  The earthquake killed 181 people in Christchurch.

There were originally six goldfish in the tank when the quake struck. When the survivors were found, there was no trace of three others. A fourth was found dead. There is the question of their missing companions. Goldfish are omnivores.

The fish spent four and a half months, trapped in their tank in a downtown area of the city, that was off-limits. There was no food, or electricity to power their tank filter. They were discovered by workers, and rescued.

The fish survived from eating algae growing on the tank’s rocks and walls. Fish can go without food for a while because they are cold blooded, and unlike mammals don't burn up food to keep warm.

How to Care for Oranda Goldfish

If you are both aquarium enthusiasts, you may want to consider oranda goldfish as your first pets together. These beautiful fish develop large hoods called wens on their heads and are as friendly as they are attractive. Understanding proper care for these delicate fish is vital for their longevity.

Educate yourself on the specific needs of oranda goldfish. Common goldfish such as the shubunken have flat, long bodies; but orandas have large, round bodies that make them slow swimmers -- they do not compete well for food with more active species. Their hooded heads are also prone to disease from bacteria and unclean water, so they are not tolerant to polluted water. In addition, unlike other types of goldfish, orandas must have stable water temperatures: not too cold, because they do not thrive if the temperatures in their tanks dips too low.

Choose a tank suitable for your fancy goldfish. Orandas do best in tanks that provide plenty of room to swim. In addition, these hardy fish may reach sizes of 10 to 12 inches (25cm to 30cm) in length, making a spacious home necessary. A long or rectangular tank with capacity of at least 20 to 30 gallons (76l to 114l) will give your pets the space they need to thrive.

Set up your fancy aquatic pets' tank with a filter and heater. Because orandas do not do well in dirty water, a filtration system will help keep their watery environment fresh and clean. An aquarium heater is a must for these fancy fish that are prone to temperature shock if their water temperatures dip too low.

To read more on this story, click here: How to Care for Oranda Goldfish

How To Keep Your Tank Safe During A Power Outage

A power outage may only be a minor inconvenience for you but, for your aquarium fish, it can be deadly.

A power outage is a minor convenience for most people – it simply means that you have to take a break from television, computer, and charging your cell phone. As long as the outage doesn’t last too long there will likely be no damage done. When it comes to your aquarium, however, a power outage can be a major problem. In order to maintain the delicate balance in your tank you need to keep your filtration system and heater running 24 hours a day, 7 days a week. Whether the outage lasts for a few hours or a few days, there are several things you can do to minimize the damage.

Types of Power Outages

Before getting into the details of how to protect your aquarium during a power outage, it is important that you understand that different types of outages will affect your aquarium in different ways. A localized power outage occurs when the main source of power to the aquarium is disrupted. This could be due to a power strip coming unplugged or a fuse being blown. In some cases the problem is easily remedied – you can just plug the cord back in or flip the switch on the circuit breaker. If the problem is due to an equipment malfunction, like a cracked heater, you may not even realize the problem right away. You may want to consider installing a plug-in alarm that will alert you if the power to your tank is interrupted – this is an especially good investment if you have a very large tank full of expensive fish. It is also a good idea that you use different plugs for different pieces of equipment so they do not all go out at once in the event of a localized power outage.

To read more on this story, click here: How To Keep Your Tank Safe During A Power Outage

How to Raise Koi

Those colorful fish you frequently see in large ponds in Japanese restaurants or shopping areas are becoming increasingly popular as the centerpiece of a backyard garden. The brightly-colored fish are called Koi, and they are the result of selective breeding of German and Asian carp. If you are considering installing a Koi pond, you should first study how to raise Koi.

1 - Select a proper pond. You can purchase a Koi pond made of several different materials from pet stores or Koi specialty retailers. A good rule of thumb is that the Koi pond measurements should be at least 3 feet (0.914 m) deep and contain 300 gallons (1136 liters) per fish. You may want to get a larger pond than you need right away, so that you can add additional fish later.

To read more on this story, click here: How to Raise Koi

Did You Know That Goldfish Were One of the First Fish Species to Be Kept in Ponds by Humans

Did you know that the goldfish are one of the most common type of pets in the world? They were one of the first fish species to be kept in ponds by humans. By nature, goldfish are social creatures and prefer to live with other goldfish.


Many people think that goldfish are pets for someone who doesn't have much time for pet care. The lifespan of your goldfish depend upon how much care you provide goldfish.  If cared for properly your goldfish could live for many years!

Goldfish start off small, but grow to be quite large, sometimes even a foot long, if you take good care of them. First time goldfish keepers usually buy a small tank or bowl to house their goldfish, only to discover that they need to keep buying ever-larger replacement tanks. You should buy a large enough tank at the beginning. You should provide a 20 to 30 gallon tank for your fish. Then add at least 10 gallons to that volume for each additional goldfish you might add. They grow large, excrete a lot of waste and need room to swim in order to be happy!

Food:    Goldfish like a diet of flakes, pellets, wafers and sticks

Goldfish Facts:

Do goldfish have ears? They have internal ear bones called an otolith that can feel vibrations. Avoid tapping on the glass since it will stress or even kill them.

A goldfish can survive in an outdoor pond where water temperatures dip down below 40*F (5*C). Some ponds might even freeze over during the winter and the goldfish still survive through to the spring.

True Story: Man Finds Half Fish and Keeps It as Pet for Six Months

A fish which lost its tail, and half its body, when it tried to leap out of a cement-lined pond no doubt thought its future looked bleak.

Amazingly, it survived its ordeal... only to end up in a tank in a Thai market, where it could well have spent its dying days.

But one man who spotted the poor creature took pity on it, adopted it and brought it home.

Watchara Chote, from Ratchaburi, named his new pet I-Half.

After its horrific accident, the fish - a hypsibarbus wetmorei - fractured its bones.

These eventually wasted away, causing the tail to fall off, according to Matichon News, the Mirror reported.

However, Chote, 36, and I-Half, were able to enjoy each other's company for six months.

During this time, he took his wonder pet to several villages to show it off.

But then, sadly, his aqua buddy passed away- whereupon well-wishers donated money for him to buy a tiny coffin.

Still, not a bad innings for a fish with half a body.

This fish lost its tail - and half its body - when it tried to leap out of a cement-lined pond.

The injured creature was spotted by Watchara Chote in a market in Thailand. He took pity on it and took it home.

Chote, 36, and his new chum - whom he named I-Half - were able to enjoy each other's company for six months.

.. but then I-Half died. Chote had taken great pride in showing off his fish to villagers, who clubbed together to buy a tiny, fishy coffin.

Floating ‘Wheelchairs’ Like These Help Sick Fish with Buoyancy Problems Stay Upright

This is the most adorable animal wheelchair we’ve ever seen. An image has surfaced of a goldfish in a sling, which people are calling a ‘goldfish wheelchair,’ designed to keep her afloat and upright.

‘Fish wheelchairs’ (or slings or buoys – call them what you will) like these are used to help fish swim upright while they recover from swim bladder infections that make it difficult for them to do so on their own. 

Green peas can help solve buoyancy issues related to constipation, but infected swim bladders or other issues may require specialized medication. Always consult your vet!

Using a simple cork, this owner saved his fish’s life

Floating ‘wheelchairs’ like these help sick fish stay upright

Swim bladder infections or constipation can make it hard or impossible to swim with balance

There are professional veterinary versions, too!

Piranhas Make Interesting Pets: Depending on the Species, Adult Piranhas Can be 12 -16 Inches Long

Piranhas can make interesting pets with their full sets of sharp teeth and their fast and furious attack skills. Keeping piranhas is a bigger commitment than keeping other fish as pets -- they require lots of space, and they can live more than 20 years in captivity. Meanwhile, their food and water temperature needs are rather simple to accommodate.

Room to Move
Piranhas can seem cute when they're small and hiding among tank decorations much of the day, but they don't stay small. Depending on the species, adult piranha can be 12 to 16 inches long. They come from river environments and live best in large tanks -- a 100-gallon tank suits a single adult piranha; add 20 gallons for each additional piranha. Red-bellied piranhas tend to school in the wild, so you can likely keep a few in the same tank, although they might attack each other at some point. If you're keeping a black piranha as a pet, house him alone -- he's just as likely to eat another piranha as the dinner you provide him.

Ringing the Dinner Bell
Piranhas aren't strictly carnivores, although meat is definitely their meal of choice. If you have aquatic plants in your tank, you might see your fish take a few bites here and there. They also eat fish pellets and flakes occasionally, and they can benefit from the vitamin boost these foods provide. But for most of their meals, plan on feeding protein such as krill, mealworms, earthworms or feeder fish. Unless you raise your own under controlled conditions, thaw frozen versions of these foods or buy live ones from reputable fish food suppliers. Avoid grabbing insects and worms from your yard -- they might have ingested chemicals such as pesticides and herbicides, which they can transfer to your piranha. Juvenile fish need to be fed up to four times per day, while sub-adults usually need food about twice a day. Feed mature adults about once every two days.

Home Sweet Tank
Piranhas can survive in a variety of tank conditions, but they prefer a water temperature of between 78 and 82 degrees Fahrenheit and a sandy substrate. Juveniles are especially fond of aquatic plants. In the wild, they spend much of their time hiding from predators until they reach their adult sizes. However, adults enjoy swimming among the plants as well. They also like large pieces of driftwood that offer secluded places to rest.

Keeping It on the Up and Up
Before buying a piranha for a pet, check with your local and state regulations. Many states ban piranhas because people sometimes release them into the wild; introducing non-native species can wreak havoc on your local environment. Non-native species can compete with indigenous ones for food, sometimes endangering the other species' survival. Also, state governments often don't want to risk local fisherman catching piranhas unexpectedly and potentially becoming injured. Even if you have no intention of releasing a pet piranha, always follow local regulations.

Safety First
Owning a piranha means taking a few precautions to ensure he doesn't decide your hand looks tasty for dinner. Even small, a piranha has razor-sharp teeth that can easily bite through your skin; as an adult, he can bite through bone to remove entire fingers. To prevent injury to yourself, never dip your hand in the water to feed a piranha. Also, don't place a hand with a wound, even a small scratch, in or near the top of the water -- the blood might attract the piranha, who swims powerfully enough to jump out of the water. Clean the tank with long tools instead of putting your arm inside, and use a net to catch your fish when it's necessary to move him. He can bite through the net, so don't stabilize him with your hand. Instead, hold a second net under the first to catch the fish if he bites a hole in the first net and falls through.

Arkansas Game and Fish Commission Authorities Confirm: Fish Caught by Fisherman is a Piranha

A fisherman caught a piranha while fishing on an Arkansas lake last week, Arkansas Game and Fish Commission authorities confirmed.

Roger Headley was fishing on Lake Bentonville Friday when he caught the toothy fish, which he thought was a large perch.

Headley told a television station the fish actually did try to bite him when caught.

“I knew he kind of looked funny, and when I reached down and tried to take the hook out of his mouth, that's when he opened up his mouth and tried to bite me,” he said.

The Arkansas Game and Fish Commission lists piranhas among species of exotic animals that are unlawful to import or transport.

Game and Fish experts told KHBS/KHOG-TV that piranhas, which usually are dumped by former pet owners, are not a threat because they don't last long in Arkansas' cold waters.

Headley said it was luck that the fish wasn't caught by a young child.

“If a little kid would have caught him or something he could have lost a finger or anything,” he said.

As Spc. Matthew Tattersall Prepares to Leave the U.S. Army, He Wanted to Make His Last Jump as a Paratrooper a Memorable One: So He Took His Pet Siamese Fighting Fish Along for a Selfie

As Spc. Matthew Tattersall prepares to leave the U.S. Army, he wanted to make his last jump as a paratrooper a memorable one.

So last weekend, he jumped with Willy MakeIt, his pet Siamese fighting fish.

A selfie Tattersall took of his fish, not out of water, but out of an airplane, went viral on U.S. Army W.T.F.! Moments, a Facebook community popular among troops.

"The picture got way more popular than I thought it would," Tattersall said.

Although social media users were hooked on the image (the photo got more than 15,500 likes), bosses upstream at Fort Bragg, N.C., thought the move was all wet.

Tattersall, who's assigned to 2nd Battalion, 505th Parachute Infantry Regiment, 3rd Brigade Combat Team, 82nd Airborne Division, said he's waiting for the final fallout from his aerial actions. Meanwhile, he has written a 1,000-word essay on the importance of airborne safety and professionalism in the Army.

"When it's all said and done, it wasn't all that safe or professional for me to have done that," Tattersall said.

But the 23-year-old, who calls himself "23 years stupid," said he has no regrets.

"It was worth it," he said. "I'm fully willing to embrace any consequences that come of it, and I hope they're lenient."

Tattersall, an infantryman with a deployment to Afghanistan, joined the Army in 2011, shipping to basic training in January 2012.

He will complete his enlistment on May 20.

His last jump was April 11.

"It was a daytime combat jump, but with me being so close to getting out, I didn't have any gear, so it was a Hollywood jump for me," Tattersall said.

He and his friends have long talked about doing something special for their last jump, but "no one actually went through with it," he said.

So when his turn came, "I wanted to make it awesome, and I did just that," he said.

The night before the jump, Tattersall went to Walmart and bought the fish he named Willy MakeIt.

"It's so random to have it be a fish," he said, crediting a friend for the idea.

Tattersall poked holes in the top of a water bottle so Willy could breathe. "I had his little pod ready," he said.

On jump day, no one knew about the plan Tattersall was hatching, he said.

"I kept it in my pocket, and I was as nonchalant as I possibly could be," he said. "I knew the jumpmasters wouldn't have let that fly. I knew none of the NCOs or other leaders would have let me jump. It was completely on me."

As he jumped from the C-17 and fell to the ground under the canopy of his parachute, Tattersall took a quick selfie.

"I had to be quick, but paratroopers get the job done," he said.

"... Conditions were perfect. I made sure I wasn't around anyone where it would have been a hazard," he said. "But I guess that's famous last words for anyone."

Tattersall and Willy MakeIt made it safely to the ground, and the hardy fish earned a middle name.

He's now Willy Did MakeIt, and he has big dreams.

"Willy and I are trying to go to space," Tattersall said.

But first, Tattersall hopes to be able to move on from the Army honorably. "I have big hopes and big plans for the future," said Tattersall, who aims to start college in the fall.

"I'm proud to be a paratrooper. I wouldn't change a thing about it."

According to Researchers at Australia's Murdoch University, Dumping Your Pet Goldfish in a Local Lake Can Cause Serious Ecological Sabotage

As tragic as it may be to watch Bubbles roam around the tank with nothing but a plastic treasure chest for entertainment, the truth is he wasn't meant to be in a bigger pond.

According to researchers at Australia's Murdoch University, giving in to your temptation to set him free in a local lake won't just leave you without a pet — it'll kick start some serious ecological sabotage. As revealed in a study published by their Freshwater Fish Group & Fish Health Unit, "introduced freshwater fishes are one of the major global threats to aquatic biodiversity."

And this isn't just some fish story. When dumped into a larger environment, those innocent little koi or goldfish grow at an exponential rate, introduce parasites that harm other species, and have the potential to decimate an ecosystem.

"They are eating up the food resources and using up the habitat that our native fish would otherwise be using,"research fellow Jeff Cosgrove told the Australian Broadcasting Corporation.

Even worse? They can be "extremely difficult to eradicate," says Cosgrove. In other words, they're not going belly-up anytime soon.

A Team of Veterinarians in Scotland Performed a Set of Operations on Pet Goldfish That Cost Nearly $750

Fife, Scotland - A team of vets from Inglis Veterinary Hospital, performed an extremely tricky operation - removing the eye of “Star” a pet goldfish. They also removed a lump off his aquarium partner “Nemo”, his best friend and bowl buddy.

The difficult surgery involved an exotic consultant surgeon, a vet keeping the goldfish under anaesthetic and a nurse monitoring their heart rates. The two operations cost the owner nearly $750, but she believes they were absolutely worth it. Star came into the Gordon family after a being won at the local fair for pocket change.

Star, was won at a fairground stall 12 years ago, had to get a blind, cancerous eye removed.

The operation was carried out on the six-inch fish at Inglis’ 24-hour hospital by exotic animals expert Brigitte Lord.

She said: “This is a highly specialist field, using anaesthetic on a goldfish carries a very high risk, and I'm delighted for the owner that everything went well and the owners are happy.”

“The financial value of a goldfish may be quite small but I think the fact that someone should have paid that much for an operation reflects the true value of the bond between pets and humans.”

During the operations, the vets used Doppler ultrasound equipment to listen through earphones to pulse sounds in order to evaluate Star's blood flow. To keep the fish asleep throughout the procedure it was syringed with oxygenated water with anaesthetic in it.

After the operation, Star was delicately held in a bucket of oxygenated water and, with its mouth kept open, was gently moved (mimicking the swimming action and allowing water to flow over the gills) for around eight minutes before it effectively came back to life. Nemo had more straightforward surgery to remove a lump on him too.

Star and Nemo are kept in Janie Gordon's home in Dollar, but are owned by her 21-year-old daughter Abby, a student in Glasgow.

 “I know it seems like a lot of money to spend on an operation for a goldfish but what was the alternative? I think we've a social responsibility to look after our pets and I know my daughter would have been distraught if anything had happened to the goldfish.” said Janie.

Janie didn’t want Star to be lonely so had bought another fish in a pet shop after her daughter won him by throwing a ping-pong ball into a goldfish bowl. Both Star and his lifelong companion, Nemo, are now over their buddy surgery and happily reunited - holding pride of place in a tank in Janie's kitchen.

“Star is fine,” said Janie. “He’s swimming about happily and the vets have shown me how to give antibiotics too”.

“I probably couldn't have chosen a better vets. I'm not sure anyone else would have attempted it.” said Janie.

Are You Making These Mistakes Setting Up A New Aquarium?

With the availability of mini-aquarium packages it's become appealing to go small. However, for beginners, choosing a small aquarium is courting failure. Why? Because when the water volume is small, key water parameters change very quickly, leaving no room for error.

Starting Too Small

Even experienced aquarists are challenged by a small aquarium. Newcomers to the hobby, stay away from tanks under 20 gallons until they've gotten some experience under their belt. Remember, the bigger the tank, the less impact a mistake will have on the fish.

Adding Fish Too Soon

New aquarium owners are eager to add fish, often the same day they set up the tank. Some are lucky but many will quickly lose some, or all, of their fish. What went wrong? The water in a new tank hasn't stabilized yet. Gases are dissolved in the water, as well as minerals, heavy metals, and chemicals added by local water treatment facilities.

Without going into lengthy detail about water chemistry, suffice it to say that dissolved constituents in the water can harm the fish. Aquarium water should be treated to neutralize harmful materials, and allowed to stand for a day or so to allow dissolved gases to escape and the pH to stabilize. Only then is it safe to introduce fish to the aquarium.

Adding Too Many Fish at Once

The fish owner isn't eager to fill the tank with fish? Unfortunately adding too many fish all at once is another common new owner mistake. Until the bacterial colonies have fully established, the aquarium cannot safely support a full load of fish. Only add a couple of
small hardy fish initially. Wait until both the ammonia and nitrite levels 
have risen, and then fallen to zero, before adding more fish.

Overstocking

Even getting through the initial startup, it's very common for new owners to overstock the aquarium. Although an experienced person may successfully keep a school of twenty small fish in a ten gallon aquarium, it would be disastrous for a beginner to attempt it.

Debate exists over the inch per gallon rule, but it provides a good basic yardstick from which to start. I recommend taking eighty percent of the net gallons of water in the tank as the maximum number of inches of fish to keep in the tank. The net gallons of water is the amount of water actually placed in the aquarium after the gravel and decorations a in it.

For example, lets say an aquarium holds 16 gallons of water after the decorations and gravel have been added. Multiplying a 16 times 80% yields a result of 12.8 - or about 13 inches of fish as a maximum number. It is always wise to go under the maximum to rather than all over.

Keeping Incompatible Fish

New aquarium owners often choose fish that look appealing to them, without knowing the environmental needs of the fish. Some fish may fight with one another, or require widely different water conditions. Either way, they should not be kept together. Always research each species before choosing tank mates. Select peaceful fish that thrive in similar water conditions.

Overfeeding

The number one mistake made by fish owners is overfeeding their fish. Fish are opportunistic and will seek food at all times. Just because they appear hungry, doesn't mean they need to be fed all the time. Feed them no more than is completely consumed in five minutes.

During startup feed fish no more than once per day, and during critical times when ammonia or nitrite levels are high, withhold feeding for a day or two to reduce the wastes being produced. Fish can easily go several days without food, and not suffer ill effects.

Insufficient Filtration

An aquarium filter should filter all the water in the tank through it at least three times per hour. If it doesn't, it is too small. If in doubt about filter size, move to the next size up. You can't over-filter, but you can definitely under-filter, and the results can be harmful to your fish.

Not Testing the Water

New owners aren't magically given full knowledge of the nitrogen cycle, and the need to monitor the water chemistry in their aquarium. As a result they often are unaware of the need to test their water, and fail to take steps to deal with harmful toxins.

When the tank is first set up, it should be allowed to run for a day or two. Before adding the fish the pH, hardness, ammonia, and nitrite levels should be tested for a baseline record. During the startup cycle it is important to test the ammonia and nitrites often (see Nitrogen Cycle for details). Once the tank is well established, test the water monthly to be aware of unseen problems that may be brewing. If fish suddenly die, test the water to see if anything has changed.

Not Changing the Water 

On other area that new owners aren't always educated about is aquarium maintenance, which includes changing part of the water on a regular basis. Wastes build up in the tank that can only be removed by vacuuming the gravel and removing some of water and replacing it with fresh water.

Although your fish may not die if you fail to maintenance and regular water changes, they will be stressed by substandard water conditions. As a result they will be more susceptible to disease and often will have a shorter lifespan than they should have.