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What Not to Do When You Begin a Tropical Fish Tank at Home

The Ultimate Guide to Mistakes Commonly Made by Aquarium Beginners

Every year, thousands of people discover the magic of having a fish tank in their homes. It gives them the opportunity to not only observe a whole different world but also to play a part in creating it. However, although this extraordinary hobby can bring hours of joy, it can have a steep learning curve attached. Unless you have superpowers or are super talented, taking on any sort of new project for the first time in your life will likely not go 100% according to plan.

Don’t let this deter you. We all know that practice makes perfect and putting together a home aquarium is no different. Here are some common mistakes beginners tend to make and what you can do to avoid making them.

70gl. Reef Tank

1. Adding Fish Too Early

I have yet to meet somebody with an aquarium who has not made this mistake at least once. It’s so exciting to get a new fish tank and all the equipment that you generally want to set up shop immediately. Once everything is set up with the filter going and the tank nicely decorated, all you need is some fish to make it come to life! Wait. Don’t be tempted. Make 100% sure your tank has stabilized before you begin adding your fish. If you don’t, they could die. A stable fish tank means that water parameters like pH, hardness, and temperature are stable.

Of course, that means that you should not be buying the tank and the fish at the same time. Get the tank and equipment first, set it up, make sure your water is stable, research different species of fish, and decide which ones suit you. Only THEN should you go out and buy fish.

2. Buying a Small Aquarium

You know the saying, “go big or go home!” This is particularly true for home aquariums. Although you may think that the tank may be easier to maintain if it’s smaller, that is not exactly true. For beginners, it may be tempting to choose one of those small aquarium starter packs. Retailers make it look like you can buy everything you need in one go. Unfortunately, what beginners don’t know is that they may be setting themselves up for failure by settling on a tiny tank. With smaller water volume, the main water parameters in the aquarium are liable to change very quickly, and fish can become ill and even die.

It is a lot simpler to maintain water parameters in a larger tank. It’s also a lot more impressive to have a large tank with a diverse collection of fish on display.

3. Beginning with a Small Filter

This is yet another reason to stay away from aquarium starter packs. Even the larger versions usually don’t come with big enough filters. It’s important to buy a filter that will turn the water over an absolute minimum of three times every hour. Anything less than that can affect the health of your fish. If you’re not sure about what size filter to use, go one size up. The good news is that it is not possible to over-filter your aquarium water.

Saltwater Aquarium 018

4. Not Understanding the Nitrogen Cycle

This is known as one of the most confusing aspects of keeping fish, and beginners usually either ignore it completely or obsess over it. It actually isn’t that complicated. In a nutshell, if the nitrogen cycle stalls, it is because the tank does not have enough beneficial bacteria, which is needed to break nitrite down into nitrate. A nitrite overload is usually caused by a build-up of ammonia in the tank from fish waste and it is toxic to fish, which is why the beneficial bacteria is so important. Luckily, unless you develop massive problems, this can usually be maintained by making sure you test your water regularly and keep an eye on nitrite levels. When they spike, it’s time to do a partial water change, which is something you should be doing regularly anyway.

5. Poisoning the Fish

Just as human beings need air around them to survive, fish need water. And what happens when this water is toxic? The same thing that happens when we breathe in toxic air. Believe it or not, it is actually quite a common thing for beginners to poison their fish by accident. This is mainly caused by:

  1. Not understanding how the nitrogen cycle works

  2. Using too many chemicals unnecessarily

  3. Overfeeding

  4. Allowing waste to accumulate in the tank

  5. Regularly turning the filter off over periods of time

6. Adding Too Many Fish at a Time

The more the merrier, right? Wrong! If you add too many fish to your aquarium, especially at once, it can destabilize the water chemistry and cause the nitrogen cycle to stall. Stick to adding a maximum of three fish at a time. Once they’ve been added, wait a while until they are settled in and test your water before adding any more to the tank.

7. Overstocking

Even if you add only three fish at a time, it is not a good idea for a beginner to keep too many fish in an aquarium. This simply requires too much maintenance. While somebody with experience may be able to successfully keep larger stocks of fish, it could be disastrous for a beginner to attempt it. Just adding fish after fish could also lead to another common beginner mistake—keeping incompatible fish.

8. Keeping Fish That Are Not Compatible

There are so many stunning fish species that it’s difficult to resist buying a new type of fish every time you come across one! Unfortunately, not all fish are compatible. They may need completely different water conditions, or they may fight with one another. Some fish (like Bettas) are so aggressive, they have to be kept completely alone. Before choosing tank mates, make sure you thoroughly research each species. Your best bet is to choose peaceful fish who enjoy similar water conditions.

9. Overfeeding

This is probably the most common mistake a beginner can make. Fish are a bit like puppies. They are constantly on the lookout for food and will eat everything in sight, even if they’re not hungry. Just because your fish dart around on the hunt for food doesn’t mean that they are hungry, and if you feed them too much, they will produce excessive waste, which can mess up the nitrogen cycle. The rule of thumb with feeding fish as that they should not be fed more than what they can completely consume within five minutes. It is usually enough to feed fish only once a day. They can even go without food for several days without suffering any ill effects. When ammonia or nitrite levels spike, it is best to withhold feeding for a couple of days to help reduce waste until the water stabilizes again.

10. Not Testing the Water Regularly

An aquarium is not just an ornament for you to look at and clean every now and then. Fish are living beings and need to be cared for just like dogs, cats, and birds. Part of this care is keeping their environment safe and comfortable. With new aquariums, the water should be tested every single day. Once the stability of the tank is established, you’ll only need to test the water once a month or when your fish are behaving weirdly or die unexpectedly. You should be checking the following:

  1. Ammonia

  2. Nitrites

  3. Nitrates

11. Not Changing the Water Regularly

There are so many new aquarium owners who have no idea that they have to regularly change part of the tank water. Waste produced by fish begins to build up in the tank and can only be removed through regular maintenance. The gravel has to be vacuumed, and some of the water has to be removed and replaced with fresh water. If this is not handled properly, the fish will become stressed by the poor water conditions and become more vulnerable to disease and even death.

12. Not Treating Algae Properly

You wouldn’t enjoy swimming in a pool full of algae, would you? Even though the natural habitat of the fish does have algae, that does not mean that it is healthy for a home aquarium. A tank is so much smaller than a river or an ocean. Algae usually begin to develop because the aquarium is not being cleaned well enough or often enough, or when it is left in direct sunlight. If you see algae in the tank, remove it immediately and give the tank a thorough cleaning. To prevent it from returning, you could consider adding live plants to the aquarium.

Begin with the Basics

As with everything else in life, the first few days or months of starting something new can be daunting. The trick is to begin with the basics and to try to avoid the most common beginner mistakes. If you keep referring back to this guide, you will soon see how important these basics are to keeping a beautiful and healthy aquarium.

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