Must-Have Fish Tank Accessories for a Healthy and Beautiful Aquarium

Feeling unsure about which fish tank accessories you actually need? We’ve all been there! Let’s cut through the confusion and help you figure out exactly what your aquarium needs to thrive. 

Top 10 Fish Tank Accessories

Here are the must-have fish tank accessories. 

1. Filter

The filter is your tank’s life support system — they’re extremely important (which is why it’s number one on this list). Filters help keep the water clean and safe by removing substances like ammonia and nitrites, both of which are highly toxic for your finned friends. And you’re right, we have the nitrogen cycle to thank for that. 

Here’s a quick ‘n easy 101 about aquarium filters: 

• Mechanical filtration: Traps debris like leftover food and waste.
• Biological filtration: Grows beneficial bacteria to break down harmful toxins.
• Chemical filtration: Removes impurities using materials like activated carbon.

Tip: Choose a filter rated for your tank size, and rinse (not scrub) the filter media during maintenance to keep the good bacteria alive. 

2. Heater

Most aquarium fish are tropical and need warm, stable water to stay healthy — no one likes sudden chills! A heater maintains the ideal temperature, usually between 75-80°F, depending on the fish. So please, do thorough research on your finned friends’ temperature needs. 

Tip: Get a heater designed for your tank size (about 5 watts per gallon). Pair it with a thermometer to ensure your fish aren’t swimming in water that’s too hot or too cold. Speaking of… 

3. Thermometer

While the heater does its work, the thermometer double-checks its accuracy. Listen — fish can be quite sensitive to even the smallest of temperature changes, which is why this is one of the must-have fish tank accessories. 

You can choose from different fish tank thermometers, like: 

• Stick-on (LCD) thermometers 
• Floating or standing thermometers 
• Digital thermometers

Tip: Place it away from the heater so you get a more accurate reading of the overall tank temperature. 

4. Lighting

Lighting isn’t just for looks — though it does make your fish and tank decorations shine! It’s also essential for live plants to photosynthesize and grow. 

Tip: Choose a light that matches your tank’s needs (e.g., plant-specific lights for planted tanks). Fish need a natural day-night cycle, so keep lights on for about 8-12 hours a day.

5. Substrate

Substrate is another important accessory. It provides a natural base for the tank, supports plant roots, and houses beneficial bacteria. In some cases, substrate isn’t needed — like with grow-out tanks and quarantine tanks — but for the majority of cases, it is needed. 

The different types of substrate include: 

• Gravel
• Sand
• Pebbles
• Soil
• Water-changing substrates

Tip: Rinse substrate thoroughly before adding it to your tank to avoid cloudy water.

6. Water Conditioner

Not all water is created equal — tap water contains chlorine and heavy metals that can harm your fish. A water conditioner is one of those fish tank accessories that everyone needs. Why? Because it helps make tap water safe by neutralizing these chemicals. 

We love and have used the following water conditioners for years now: 

• Seachem Prime
• Seachem Stability

Tip: Always treat water with a conditioner before adding it to your tank, especially during water changes.

7. Test Kits

Healthy water is the foundation of a happy tank. Test kits help you monitor water quality, so you’ll know if there’s an issue before it harms your fish.

You’ll typically test for: 

• Ammonia
• Nitrite
• Nitrate
• pH

Some kits also check water hardness and chlorine. If you want recommendations, we’ve always used the API Master Test Kit and, recently, Seachem’s Ammonia Alert. 

Tip: Liquid test kits are more accurate than strips. Test weekly to ensure everything stays balanced.

8. Gravel Vacuum

Over time, waste and leftover food settle into the substrate — even if you do have a filter! Both a filter and vacuum are must-have fish tank accessories. That now said, a gravel vacuum lets you clean up this mess while removing water for regular changes.

Tip: Use it during water changes (every 1-2 weeks). It’s like giving your tank a quick spring clean without the stress of a full breakdown. Learn how to siphon with our easy step-by-step guide with pics!

9. Net

It goes without saying — a net is handy for moving fish safely, whether you’re doing maintenance or transferring them to another tank. 

Tip: Get a soft, fine-mesh net that won’t harm delicate fins. Use it gently to avoid stressing your fish.

10. Decorations

Okay, okay, for some, this may not be a must-have accessory — but it’s more important than you might think. Decorations make your tank look fantastic while creating hiding spots where fish can feel secure, reducing stress. 

For example, you can add: 

• Rocks
• Driftwood
• Caves
• Plants (live or artificial)

Tip: Choose aquarium-safe items (no sharp edges or harmful materials). Rinse the decorations before adding them to the tank.

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This app has everything you need to build and maintain a thriving tank. Not sure which fish are compatible? Wondering about pH or tank size? Aquabuildr’s intelligent algorithm has your back with personalized recommendations that take all the guesswork out.

Your fish deserve the best, and so do you. Download Aquabuildr today— it’s on the App Store or Google Play Store — and start building your dream aquarium with confidence.