There are numerous mistakes I made during my initial stages of fishkeeping, but I’ll focus on 8 key errors to provide you with a foundation and help you mature in your hobby.

Not knowing your fish

I made several mistakes initially, but this one stood out the most. It’s crucial to understand the requirements of your fish, including their common diseases, preferred living conditions (such as group or solitary habits), and compatibility with other fish.

For instance, tetras thrive in groups of 4 to 6, while certain species have specific water parameter needs. It’s essential to research your fish’s preferences, habitat, and potential diseases before introducing them to your tank.

Pro tips: Before getting the fish from the store, know how they breed that fish and understand its common behavioral patterns. That’s all it takes.

Excessive water changes

New aquarists often rush to change water at the first sign of cloudiness or debris. However, it’s important to exercise patience as some issues can be resolved with natural remedies. Frequent water changes aren’t always necessary, except during the cycling process, where they can be beneficial.

Pro tips: I saw many of my friends change water (50% or whole) every week regularly. You shouldn’t do that if you have enough plants and filtration; you don’t need to change water so often in that scenario.

Improper cycling of the aquarium

Before adding fish, it’s crucial to wait for the cycling process to complete. There’s an ongoing debate about whether to opt for fishless cycling or fish-in cycling. As a beginner, I recommend fishless cycling, which typically takes 2 to 3 weeks to establish the necessary bacteria and convert ammonia and nitrites into nitrates.

Pro tips: Don’t use any quick formula to cycle immediately; remember, it’s a process, and in the long run, you have to do it the hard way.

Overfeeding

This is a common mistake among new aquarists, driven by an abundance of care for their fish. It’s important to remember that fish are wild creatures accustomed to periods without food.

I used to feed my fish every time I passed by the tank, but this practice can lead to overfeeding and waste accumulation in the tank. One another mistake you might make by seeing 3X feedings every day in the back of your food, which I found cruel.

Now I feed once a day but here a funny thing happens to me, my fish start to nip at each other if I don’t feed them on time. It’s essential to strike a balance and feed your fish appropriately to avoid health issues and water contamination. Honestly, they can go unfed for 2-3 days without any issues.

Pro tips: Feed only as much as doesn’t stay on the water surface for more than 1.5 – 2 minutes. What I love to do is I don’t feed all at once; firstly I pour some food, then those who have finished eating go to the bottom, and then I feed the other half to my other fish. Finally, try to keep a variety of diets.

Incompatible fish mates

Incompatible fish refers to those that are not suitable for your existing fish. However, I’ll broaden the term by mentioning that it can also include introducing new sick fish to your tank, which would also be incompatible.

Therefore, proper quarantine of fish and introducing the right tank mates is crucial. For example, having male betta with female bettas will be dangerous unless you are breeding, as well as keeping more than 1 male betta can lead to aggressive behavior. Another example from my beginner stage is when my guppies turned out to be aggressive toward bettas, nipping their fins, which was unfortunate. So it’s essential to keep these things in mind.

Pro tips: Have knowledge about common enemies and compatible tanks. Sometimes incompatibility varies with the size of the tank, so spend time with your fish to check what is best suited for them.

Temperature

Here you may need a heater in most cases or maybe not, depending on the fish. But roughly saying, more or less every fish can survive easily between 70 to 77 degrees Fahrenheit, but it varies from fish to fish. If you don’t have a heater, the tank might get cold, which may not be suitable for every fish. One exception I will mention is fancy goldfish; they are likely to survive in cold water. Other than that angelfish prefer warmer water (77 to 8 degrees).

Pro tips: Don’t make sudden fluctuations in temperature in the tank; it may stress out your fish and cause sickness.

Oxygenation vs. Agitation

Let’s delve into a less conventional aspect of aquarium care. Recall the simple pleasure of throwing stones into a pond during your childhood. What did you observe? Ripples or wavefronts expand across the surface, right? Similarly, in an aquarium, consistent surface agitation generates oxygen by agitating the water’s surface, creating waves. While this benefits the surface, it may not suffice for the entire aquarium.

This is why I prioritize aeration over surface agitation. Throughout my 15 years of dedicated hobbyist experience, I’ve focused on ensuring optimal flow rates rather than fixating solely on surface agitation, and I’ve encountered no issues as a result.

Pro Tip: Maintaining a robust flow rate throughout the aquarium alleviates the need to obsess over surface agitation, as both methods ultimately serve the common purpose of oxygenation.

Overcrowding

One common mistake often made by novice aquarists is overcrowding their tanks. The question arises: How do you determine when your tank is overcrowded? There’s no one-size-fits-all answer to this query. First, let’s discard arbitrary capacity rules such as the inch-per-gallon or square-inch formulas. Consider this scenario: a single fish measuring 10 inches in a 10-gallon tank may indeed lead to overcrowding, but the same fish in a 50-gallon tank would not pose such an issue.

I’ve housed 40 small fish in my 30-gallon tank without encountering problems. Understanding your fish species and their specific requirements, including breeding tendencies, adult size, temperament, and compatibility with tankmates, is crucial in determining appropriate stocking levels.

Pro Tip: Prioritize understanding your fish species before making additions to your aquarium. Familiarize yourself with their adult size, temperament, and compatibility with other species to avoid the pitfalls of overcrowding.