Aquarium Fish: How to Choose the Right Fish for Your Aquarium

Choosing the right fish is the key to a beautiful and healthy aquatic ecosystem. Whether you're a beginner or an experienced aquarist, selecting healthy and compatible fish is essential. But don’t worry, iFISH Store has all the answers to your questions! Here are the three key rules to consider:

Rule 1: Match Tank Size

The first and most critical rule is to ensure your chosen fish are a good fit for your tank's size. A small fish in a large tank is often fine, but a large fish in a small tank is a recipe for disaster. We've seen it all too often: a beautiful fish like a Discus or an African Cichlid purchased as a juvenile only to outgrow its home, leading to stunted growth, stress, and poor water quality.

When browsing our selection of fish like Angelfish, Arowana, Barbs, and more, always check their maximum adult size. A general guideline is to allow ample space for each fish to swim and establish a territory. Our detailed product descriptions provide you with the information you need to make an informed decision. For schooling species like our popular Neon Tetra Bulk Packs, a longer tank is ideal to give them the space they need to shoal comfortably, reducing stress and showcasing their natural beauty.

Rule 2: Check Water Parameters

At The iFISH Store, we ensure our fish are raised in pristine, ideal conditions, and we want you to provide the same for them. The water in your aquarium is your fish's home, and the parameters must align with their natural habitat. The two most critical parameters are temperature and pH.

• Temperature: A stable temperature is vital for the health of your fish. All of our tropical fish, from our Discus Bundles to our Guppies, require a heated tank to thrive. We recommend a reliable aquarium heater to maintain a consistent temperature, typically between 75−80°F, which is the optimal range for most of our offerings.

• pH: The acidity or alkalinity of your water is just as important. For example, our African Cichlids from the Rift Valley lakes thrive in alkaline water with a pH of 7.8-8.5. In contrast, many of our South American species, like Discus, prefer a slightly acidic pH. It’s crucial to know your tank's pH and choose fish that are compatible. To help you, we offer a Freshwater Fish Compatibility Chart on our website, a resource we highly recommend you review.

Rule 3: Assess Temperament

A peaceful aquarium community is a happy one. Mixing fish with incompatible temperaments can lead to stress, aggression, and unnecessary fatalities. When you select fish from our store, whether it's an individual or a part of a bundle, it’s essential to consider how they will interact.

We provide a wealth of resources, including our African Cichlid Guide and Discus Fish Guide, to help you understand the social dynamics of your chosen species. For instance, our African Cichlids are known to be territorial, so it's important to provide plenty of hiding spots. Our bulk packs of schooling fish like Neon Tetras are designed to allow them to live in groups, which is a key part of their natural behavior. 

Always avoid placing aggressive fish with timid species or those with long fins that could be an easy target for fin-nippers. By carefully considering temperament, you'll create a harmonious community that you'll love to watch.

For a more detailed compatibility chart, you can visit our compatibility chart page.

 

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Beginner-Friendly Aquarium Fish (Top Picks)

For new aquarists, it's best to start with hardy species that are easy to care for. The following table highlights some top picks for freshwater aquariums:

For more options, explore our collections: Guppies, Tetras, Catfish, Pleco, Gourami, Angelfish, and African Cichlids.

 

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Setting Up Your Aquarium

Stocking Rules & Calculator

To maintain water quality and fish health, follow these rules for stocking your tank:

• Start Light: Initially, stock your tank at 30–50% of its capacity to allow for effective monitoring of water quality.

• Monitor Ammonia/Nitrite: Test the water weekly to ensure safe levels for your fish.

• Add Slowly: Introduce new fish gradually, waiting several weeks between additions to maintain stability.

Example Calculation: For a 20-gallon tank, aim for 6–10 fish to start. Explore our Starter Deals for a quick and easy start.

Water Parameters Made Simple

Keeping your fish happy and healthy requires maintaining the correct water parameters:

• Temperature: Most freshwater fish thrive in a temperature range of 72-78°F.

• pH Range: Aim for a pH of 6.5-7.5 for most beginner-friendly species.

• Hardness: Maintain stable General Hardness (GH) and Carbonate Hardness (KH) levels suitable for your chosen fish species.

Make sure your aquarium has the right heaters and conditioners. For more information, visit our Fish Diseases guide.

Compatibility & Community Setups

Compatibility among species is vital for a successful community tank. Refer to our official Compatibility Chart for guidance.

Proven Community Layouts:

• 20 Gallon Long: Guppies, Tetras, and Corydoras

• 75 Gallon Tank: Angelfish, Gourami, and Plecos

• 120 Gallon Tank: African Cichlids with various Tetra species

 

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Adding New Fish: Acclimation & Quarantine

Proper acclimation and quarantine are crucial to help new fish transition smoothly.

Acclimation (Floating Method – Step-by-Step)

1. Float the Bag – Place the unopened bag with your fish in the aquarium for 15–20 minutes to let the temperatures equalize.

2. Introduce Tank Water – Open the bag and gradually add a small amount of your aquarium water every 5 minutes for 15–20 minutes.

3. Transfer the Fish – Using a net, gently move the fish from the bag to your aquarium. Do not allow any store water into your tank.

Quarantine (Protect Your Tank)
We strongly recommend quarantining all new fish before introducing them to your main aquarium. This simple step can prevent illness and protect your existing fish.

• Separate Tank – Place new arrivals in a dedicated quarantine tank for 2–4 weeks.
  
  

• Observation – Watch closely for any signs of disease or unusual behavior.
  
  

• Feeding – Feed lightly and keep the environment clean.
  
  

• Preventive Care – This period allows you to treat any potential health issues before they spread to your display tank.

For full instructions, see our Acclimation Guideline.

 

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Maintenance Schedule: First 30 Days

Follow this schedule to help establish your new aquarium:

• Day 1-3: Set up your tank and establish the filter.

• Week 1: Test water parameters and perform the first water change (10-20%).

• Weeks 2-4: Continue testing the water weekly and adjust your maintenance routine based on the results.

For additional tips, check out our Blog.

 

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Buying Guide: Online vs. Local

You can purchase fish from online stores or local retailers.

Online Benefits:

• Selection: Online stores often offer a wider variety of fish.

• DOA Policies: Check shipping guarantees to ensure your new fish arrive healthy. See our Shipping & Return FAQs.

• Quality of Packaging: Our packing standards ensure the highest quality during shipment. Learn more about how we pack live fish.

In-Store Benefits:

• Health Checks: You can see the fish in person to assess their health before buying.

• Immediate Pickup: Take your new fish home right away without waiting for delivery.

 

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Where to Buy an Aquarium Near Me in Richmond Hill, NY!

Ready to find the perfect companions for your new aquarium? Explore our wide selection of healthy freshwater fish and invertebrates at The iFISH Store! We offer quality, variety, and a live arrival guarantee, delivered right to your door.

You can also visit us in person at 89-43 127th Street, Richmond Hill, N.Y. 11418. Have questions? Feel free to reach out via email at info@theifishstore.com or give us a call at 516.524.6423. We're here to help you create a thriving aquatic environment!

Frequently Asked Questions

What are the three most important things to consider when choosing fish?

The three most important rules are to match the fish to your tank size, ensure they are compatible with your water parameters (temperature and pH), and check their temperament to avoid aggression in your tank.

How many fish should I put in my new aquarium?

Instead of following the "inch-per-gallon" rule, focus on bio-load. It's recommended to start light by stocking your tank at 30-50% of its capacity. For example, a 20-gallon tank should start with 6-10 fish. This allows you to monitor water quality and add more fish slowly over time.

What are some good beginner-friendly fish?

Hardy and peaceful species are great for beginners. Some top picks include Guppies, Tetras, Corydoras (Catfish), and Gourami, which are known for being robust and easy to care for.

How do I properly add new fish to my tank?

Proper acclimation is key. First, float the bag in your tank for 15-20 minutes to equalize the temperature. Then, use the drip method for 30-60 minutes to slowly introduce your tank's water to the fish. Finally, net the fish into your tank, avoiding adding any of the store's water. It is also highly recommended that new fish be quarantined in a separate tank for 2-4 weeks.

Is it better to buy fish online or from a local store?

Both options have benefits. Online stores often offer a wider selection and have detailed shipping guarantees. Local stores allow you to see the fish in person to assess their health and take them home immediately without waiting for delivery.