5 Common Aquarium Problems and How to Fix Them

Setting up your first aquarium or even maintaining one for years can be a rewarding experience. There’s something magical about watching fish glide through clear water, plants sway gently, and an entire underwater ecosystem flourish right in your living room. But as any aquarist knows, aquariums come with their fair share of challenges.

Over time, you might notice issues creeping in: cloudy water, stressed fish, or even algae taking over your beautiful tank. Don’t worry these problems are common, and the good news is they’re usually easy to fix once you know what to look for. Let’s explore five of the most common aquarium problems and how you can solve them.

1. Cloudy or Murky Water

You fill your tank with sparkling clean water, and within a few days, it’s looking cloudy. This is one of the most common concerns for aquarium owners, especially beginners.

Why it happens:

• Bacterial bloom from a new tank (totally normal! Do nothing and let it settle naturally)

• Overfeeding or uneaten food

• Inadequate filtration

• Too frequent filter cleaning

• Ammonia

• Chlorine or Chloramine present

How to fix it:

• Perform regular water changes (about 30–50% weekly)

• Avoid overfeeding feed only what fish can consume in 2 minutes

• Check your filter and clean or it as needed (4-6 weeks)

With patience, your tank will clear up naturally as the ecosystem balances itself. Ensure you have adequate biological media for your beneficial bacteria to grow and function.

2. Algae Overgrowth

A green film covering the glass or fuzzy patches on decorations can ruin the beauty of your tank. While some algae is normal, excessive growth indicates an imbalance. There are many forms of algae which have a wide variety of causes so please enquire if needed.

Why it happens:

• Too much light

• Excess nutrients in the water (from overfeeding or decaying matter)

• Lack of live plants or algae-eating fish

• Too warm

• Lack of flow (5x-10x LPH over the volume of water, 300 LPH for 60L tank)

• Ammonia

• Nitrifying bacteria dying due to pH swings

How to fix it:

• Reduce lighting to 6 hours a day

• Clean the tank surfaces and decorations regularly

• Gravel vacuum if gravel is present.

• Introduce algae eaters like Snails, Otocinclus, Siamese Algae Eater and Amano Shrimp.

• Avoid overfeeding and remove leftover food promptly

• Maintain temperature at 23-25C

  
  

3. Fish Stress or Disease

Your fish may hide constantly, gasp at the surface, or show unusual spots or behaviour. Stress is not only concerning to watch it makes fish more susceptible to disease.

Why it happens:

• Poor water quality

• Incompatible tank mates

• Sudden changes in temperature or environment

• Lack of GH

• Lack of numbers of their own species

• Lack of oxygen

How to fix it:

• Test water parameters regularly (pH, ammonia, nitrite, nitrate)

• Ensure species compatibility before adding fish

• Keep temperature stable and avoid sudden changes

• Maintain appropiate numbers of fish species (eg. No less than 6x Neon Tetra)

• Ensure filter is adequete and creates ripple on the surface, this ensures enough gas exchange via oxygen exchange.

  Prompt attention can prevent minor issues from turning into major losses.

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4. Foul or Strange Odours

A healthy aquarium should smell fresh, not like a swamp. Bad odours usually indicate something is decaying or water chemistry is off.

Why it happens:

• Uneaten food

• Dead plant matter or fish, snails smell even worse.

• Dirty substrate or filter

• Hydrogen Sulfide (Smells of bad eggs or petrol) created by Anorobic bacteria. (Commonly seen in tanks with thick sand due to compaction and therefore lack of oxygen.)

How to fix it:

• Remove decaying matter immediately

• Vacuum the substrate regularly, loosen up sand if there are thick layers.

• Perform regular water changes and clean the filter.

• Install surface skimmer to ensure proper gas exchange.

Maintaining a clean environment keeps your fish healthy and your tank smelling pleasant.

5. Weak or Dying Plants

Aquatic plants enhance the beauty of your tank, but they can sometimes struggle to thrive, turning brown, translucent, or decaying.

Why it happens:

• Insufficient light

• Too much light

• Wrong choice of plants

• Poor nutrient balance

• Algae competing for resources

• Lack of fertiliser

• Lack of flow

• Too warm

How to fix it:

• Ensure plants receive adequate light for 6–8 hours a day

• Use liquid fertilizers or root tabs regularly

• Remove algae and unhealthy leaves promptly

• Check the fundementals, i.e filter flow, temperature, lighting

Healthy plants not only look better but also help maintain water quality.

Final Thoughts

Aquariums are living ecosystems they’ll always have surprises. The key is observation and proactive care. By addressing issues early and understanding why they occur, you can create a thriving, balanced underwater world that brings joy every day.

Remember, patience is part of the hobby. Each challenge you face is an opportunity to learn more about your fish, plants, and the fascinating world under the water’s surface.