Common Mistakes New Fish Keepers Make in India

(Beginner Guide by Blessings Aquarium, Pune)

Starting your first aquarium is exciting, but many beginners unknowingly make mistakes that harm their fish. At Blessings Aquarium, Pune, we meet new hobbyists every day — and most of the issues we see come from a few simple errors.

To help you avoid them, here’s a beginner-friendly, India-specific guide to the most common mistakes new fish keepers make.

1.Skipping the Nitrogen Cycle (The Biggest Beginner Mistake)

New fish keepers often add fish immediately after setting up the tank. But without cycling, ammonia and nitrite rise and fish start dying within days.

What to Do Instead

• Run your tank 7–15 days before adding fish

• Add beneficial bacteria

• Test ammonia, nitrite and nitrate

2. Overfeeding the Fish

This is extremely common in India, especially with kids at home.

Problems Caused

• Water pollution

• Ammonia spikes

• Obesity and digestive issues

Correct Feeding

Feed only what fish can finish in 30–40 seconds, once or twice a day.

3.Choosing the Wrong Fish for the Tank Size

People often buy fish based on looks, not compatibility or size.

Common Indian Examples

• Goldfish in small bowls (very unhealthy)

• Oscars in 2–3 ft tanks

• Molly, Guppy, Betta kept together (not compatible)

Tip

Always ask for adult size before buying.

4.Mixing Incompatible Fish

Aggressive and peaceful fish don’t mix well.

Examples

• Betta + Guppy

• Oscar + Community fish

• African Cichlids + Tetras

Always check compatibility before purchasing.

5.Buying Fish From Unreliable Sellers

Street vendors or unclean shops often sell sick fish.

Risk

• Parasites

• Bacterial infections

• High death rate

Always choose a trusted store like Blessings Aquarium, Pune for healthy fish.

6.Using a Very Small Tank

Beginners often assume small tanks are “easy,” but the reality is opposite.

Why Small Tanks Are Hard

• Water gets dirty quickly

• Temperature fluctuates

• Fish get stressed

Start with at least a 2–3 ft tank.

7.Not Installing a Proper Filter

A big mistake in many Indian homes is using a small or cheap filter.

Good Filtration = Healthy Fish

Use a filter with:

• Mechanical media (foam)

• Biological media (ceramic rings)

• Chemical media (carbon, optional)

Internal, external, or top filters — choose what fits your tank size.

8.Ignoring Water Changes

Many beginners clean only the glass or change water once a month.

Correct Routine

Do 25–30% water change weekly, no exceptions.

9.Adding Too Many Fish at Once

Overstocking creates ammonia spikes and constant stress.

Rule

Follow the “go slow” method — add 2–3 fish at a time.

10.Sudden Changes in Water Temperature or pH

This happens often during monsoon and winter.

To Prevent Stress

• Use a heater

• Acclimate new fish properly

• Keep temperature stable for tropical fish (24–27°C)

11.Cleaning the Filter With Tap Water

Tap water contains chlorine which kills beneficial bacteria.

Correct Way

Rinse filter media using old tank water only.

12.Using Tap Water Without Dechlorinator

Chlorine in tap water burns fish gills.

Always Use

A good anti-chlorine water conditioner.

13.Adding Fish Immediately After Buying

Bag to tank transfer is dangerous.

Correct Method

Float the bag 15–20 minutes

• Slowly add tank water

• Then transfer fish

14.Not Researching Before Buying

Most problems can be avoided with a little research.

Check:

• Tank size

• Diet

• Compatibility

• Behavior

• Water parameters

Conclusion: Avoid These Mistakes for a Happy, Healthy Aquarium

Keeping fish is easy when you avoid these common mistakes. With proper care, knowledge, and high-quality products from Blessings Aquarium, Pune, your fish will thrive for years.