🐠 Diseases in freshwater aquariums – causes, symptoms & what really helps

🩺 When fish or invertebrates become ill…

Sooner or later, every aquarium owner experiences it: a fish stops eating, swims strangely, develops white spots, or shrimp behave oddly. 😟 Diseases in aquariums are a common problem – and often a sign that something in the ecosystem is out of balance .

The good news: Most diseases can be detected early, treated effectively, and even prevented with proper care . 🩹 In this article, you'll learn which diseases are common, how to recognize them, how to treat them, and how to prevent them in the future.


🔍 Common diseases in freshwater aquariums

❄️ White spot disease ( Ichthyophthirius multifiliis )

  • Symptoms: White spots on body and fins, fish rub themselves against objects, breathe heavily.

  • Causes: Sudden temperature changes, stress, new fish without quarantine.

  • Solution: Slightly increase the temperature (approx. 28 °C), treat affected fish specifically, optimize water quality.


🪸 Fin rot

  • Symptoms: Frayed or shortened fins, sluggish fish.

  • Causes: Bacterial infection due to poor water quality or stress.

  • Solution: Stabilize water parameters, separate affected animals, and use natural care products.


🐟 Fungal infections

  • Symptoms: Whitish, cotton-like coatings on the body or fins.

  • Causes: Injuries, weakened immune system, or poor water conditions.

  • Solution: Isolate affected animals, treat them with natural preparations, and improve water hygiene.


🪱 Parasitic infestation (e.g. gill worms)

  • Symptoms: Fish gasp for air, rub themselves frequently, and exhibit unusual swimming behavior.

  • Causes: Introduction by new animals or plants, weakened immune system.

  • Solution: Quarantine new animals, targeted treatment, optimize water quality.


🦐 Molting problems in shrimp

  • Symptoms: Shed skin remnants remain stuck, animals die after shedding.

  • Causes: Mineral deficiency, incorrect water quality, stress.

  • Solution: Supplement minerals, ensure stable water parameters, minimize sources of stress.


🧪 Causes – why diseases develop in the first place

Diseases almost never appear "just like that." In over 90% of cases, a stressed or unstable aquarium environment is the underlying cause. Common causes include:

  • 📉 Fluctuating water parameters (nitrite, nitrate, pH)

  • 🍽️ Overfeeding → waste products pollute the water

  • 🪸 Overcrowding or stress → weakens the immune system

  • 🐠 New animals without quarantine → Pathogens introduced

  • 🌡️ Sudden temperature changes


✅ How to treat illnesses correctly – step by step

🧪 1. Check and stabilize water parameters

Poor water quality is the most common cause of disease. Check nitrite, nitrate, and pH levels and perform a partial water change immediately if necessary.


🩹 2. Separate sick animals

Isolate infected animals to prevent the spread. Quarantine tanks help you treat them in a targeted and stress-free way.


🍀 3. Use natural support

Chemical medications should always be the last resort. Instead, opt for natural care products, mineral supplements, and stress-reducing accessories to strengthen your animals' immune systems.

👉 In our shop you will find a selection of water conditioners, minerals and natural care products that can support your fish and invertebrates and prevent diseases.


🪸 4. Strengthen the immune system

  • Feed a balanced diet

  • Avoid stress

  • Maintaining stable water parameters

  • Change the water regularly


🧠 Avoiding illness – prevention is better than cure

  • 🧪 Check water parameters weekly

  • 🪸 Always keep new animals in quarantine for 2 weeks

  • 🐌 Ensure stable conditions: temperature, pH, nitrite, nitrate

  • 🌿 Avoid overstocking

  • 🍤 Adjust the amount of food


✅ Conclusion: Illnesses are a signal – not the end

Diseases in freshwater aquariums are annoying, but almost always a sign of an imbalance . With a quick response, targeted care, and regular monitoring, you can easily manage them. 🐠💧

👉 Discover natural care products, minerals and accessories in our shop now that will strengthen your animals and keep your aquarium healthy.

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