10 Common FishKeeping Mistakes Beginners Make

Fishkeeping is frankly not easy to excel at. It requires your time, money, and if care isn’t taken, you’ll lose all of it making silly mistakes you could otherwise avoid.

As with everything, it is important you learn from others who have done what you’re trying to do. If there are books, read them. If there are videos, watch them. Speak to as many people as you can because that might just be the line between your success and overwhelming failure.

There are lots of fishkeeping mistakes beginners make and most of them will cost you not just your time and money, but also the life of your pet fish(or just fish). So here are 20 common fishkeeping mistakes beginners make and hopefully knowing them will help you avoid them.

Common Fishkeeping Mistakes Beginners Make

  1. Not Quarantining New Fish

Your fish tank is sacred and should be treated with care. Know that you can only be sure of what you already have in there and anything foreign it alien has to be properly checked before being introduced into your tank.

Some fishkeeping beginners make the mistake of buying and adding new fish into their tank without quarantining them first to make sure they are disease-free and 100% safe.

New aquarium fish can easily carry parasites like ich and velvet and the sure way to ensure you don’t introduce them to your tank is to make sure they are quarantined.

It is better you find out the fish is disease-free while in quarantine than to risk your fish tank on the assumption that it is.

  1. Overfeeding

At some point, every fishkeeper has been guilty of this. It is easy to get lost in the excitement of owning a fish and you just want to fatten it up and take good care of it. So you feed it all the time, because well, food is great right? Well, wrong!

There is something fish do that can easily be confused for wan to of food. Fish occasionally come up to the surface of the water and it is easy to think they’re coming up for food.

The truth is, overfeeding is one major problem when it comes to fish keeping. There are consequences to overfeeding your fish, so if you do, you have to act quickly before you harm your tank’s water quality which in turn will harm your fish.

It is advisable you feed your fish once or twice daily. Or you can feed them very small portions often. If you plan on going away for a number of days, then you need to get an automatic fish feeder. These are great for reducing the chances of any overfeeding occurring and help to keep your fish active while you are away.

This is so because leftover food in your tank will get mouldy and cause problems.

  1. Underestimating The Running Cost

Owning and setting up a fish aquarium is pretty expensive. Not just the cost of startup, but the cost you will accrue over time. Yes, it is expensive to buy an aquarium, set it up, buy a fish and all that. It is important not to forget that there are things you will need as time goes on. There will be additional costs on other essentials like electricity, food, drugs, equipment, etc.

Be sure you can afford to foot all the future bills before acquiring a fish tank and setting it up. You have to take time out, consider and also research roughly how much you will be required to spend if you do decide to get one. When you do this, you can properly weigh your capacity and avoid a whole lot of stress in the future.

  1. Not Test Water And pH Quality

Competent fishkeepers know when and how to check their water quality but most beginners don’t. Some do not even know they have to check it from time to time.

It is important you always know what goes on in your aquarium and since you don’t live in it, the best way to do that is to regularly conduct tests whether your tank is saltwater or freshwater.

For a saltwater test, you need this aquarium test kit. You will be testing for; phosphate, nitrates, nitrite, dissolved oxygen, ammonia, temperature, pH, carbonate hardness, specific gravity, calcium content.

For a freshwater test, you need this aquarium test kit. You will be testing; pH, chlorine, temperature, ammonia, hardness, alkalinity, nitrite.

Make sure you perform these tests weekly and do so with quality test kits. By doing this, you will be kept in the know always and be in the position to get help quickly if anything were to go wrong.

  1. Purchasing The Wrong Fish For The Right Set-Up

There are a lot of factors you must consider before buying a fish. Are the fish you are buying compatible with the one(s) you already have? Are their sizes suitable for the tank you own?

Always make sure to consult experts before you make unnecessary purchases and the closest expert is the shopkeeper. They can advise you on what to buy and what not to buy so you’ll do well to listen to them to about buying the wrong fish for your tank.


  1. Buying Cheap Food.

I know sometimes, being economical is a great idea to save yourself money but pinching cash in buying food for your fish might not be a good idea. Do not make the mistake of buying cheap dried flake food for your fish because it doesn’t offer enough essential proteins, vitamins and other important and needed supplements.

You need to provide your fish with a diet that gives them the necessary nutrients and it shouldn’t be just one type of feed. Mix it up. I’m sure you won’t appreciate eating Canned beans for the rest of your life. So don’t subject your fish to that fate.

Give them a variety of food such as Bloodworms, Shrimps, and frozen food alternatives of the same. It won’t cost you much to feed your fish right, so be responsible and provide the best diets.

  1. Letting Your Neighbours Look After Your Fish While You’re Away

If you think about this kind of situation, you’ll think you only did it because you were left without a choice. Well, okay. But is your neighbour a fishkeeper too? Do they know how to take care of an aquarium as is required? You need to think about that.

Keeping your aquarium in the care of a  non-fishkeeper for more than a couple of days can breed a lot of troubles. The most common and worst of them is forgetting to or overfeeding the fish(es). We’ve already discussed what overfeeding can do to your tank and your fish.

Also, if something were to go wrong, for instance, an outbreak of disease, your neighbour will not have the slightest idea what to do and how. They can not perform routine maintenance not can they do the usual tests for water quality.

In fact, a lot could go wrong and you might come back to find your fish have died.

  1. Adding Too Many Fish Too Quickly

A common mistake beginners tend to make is adding too many fish into their tank all at once. The temptation js strong, I admit it, but doing that can cause the nitrogen cycle to fail and can also destabilize the water chemistry.

It is best you probably add 3 fish max at once and when you do that, you have to wait for the water chemistry to stabilize again before adding more fish. Going against this will lead to lots of problems for you so it’s best you listen to wise counsel.

10 Common FishKeeping Mistakes Beginners Make, Aquarium Fish Tanks UK

  1. Not Using A Lid On Your Aquarium

A lot of fish are jumpers, can’t help it. When you add some fish to your aquarium, they want to escape because they aren’t used to the new environment so you have to make sure your aquarium has a lid.

A fish that is being bullied by other fish might want to jump too. So you have to figure out a way to avoid having dead fish on your hands.

If you do not want to put a lid on your aquarium, you could try using a wire/mesh sheet on top of your tank at least for a short while after you’ve got a new fish.

  1. Buying Fish That Will Outgrow Tank Too Quickly

A lot of aquariums do not accept fish when you return them so what do you do with your fish when your aquarium can no longer accommodate it?

When you visit the store to get a fish, you’ll mostly see beautiful fish that are small and cute, so you get smitten. Now, this is why you have to have done your research before trying to a fish because most of the fish you see will grow so much within years. And buying them when your aquarium is small will become inconvenient for you in the years to come.

Some of these fish are cheap and that might tempt you. But don’t make a costly mistake in buying fish because of how it looks at the moment or how inexpensive it is. Some of the fish that quickly outgrow the tank are Catfish, Oscars and Plecostomus.

Final Thoughts

The truth is that no one is beyond making mistakes and at some point, everyone was once a beginner at that hobby they love so much. We learn daily and we grow enough to impact others so don’t beat yourself up if you’re still having some troubles knowing what to do and when.

The good news is that there a ton of people who are into fishkeeping just like you, and a lot of them are experienced. Most of them will be happy to share their experience with you so you don’t have to make the same mistakes they did. All you need to do is ask questions. Reach out to others and draw from their wisdom.

You can join groups on social media that appeals to you and gain from a community of fishkeepers. And like I said, never be ashamed to ask questions.