How to Fill a 75 Gallon Aquarium with Water, Gravel, and Decorations for Happy Fish

Looking to fill a 75 gallon aquarium? Congratulations, this is quite exciting! However, the process of actually filling the aquarium can seem overwhelming if you’ve never done it before. But don’t worry, we’ve got you covered. In this blog, we’ll walk you through the necessary steps to successfully fill your aquarium and ensure that your aquatic pets have a happy and healthy home.

So, grab a cup of coffee and let’s dive in!

Gather Necessary Equipment

When it comes to filling a 75-gallon aquarium, the first step is to gather all the necessary equipment. This includes a clean and sturdy aquarium stand, a high-quality filter, a heater, a thermometer, and a water conditioner. You’ll also need a substrate, such as gravel or sand, to line the bottom of the tank, as well as plants, rocks, and other decorations to create a natural and stimulating environment for your fish.

It’s important to choose the right equipment for the type of fish you plan to keep, as different species require different water conditions. For example, if you’re planning to keep tropical fish, you’ll need a heater to maintain a warm and consistent temperature. Once you have all of the necessary equipment, you can start the process of filling your 75-gallon aquarium with water and preparing it for your fish to call home.

75-Gallon Aquarium

When setting up your 75-gallon aquarium, it’s important to gather all the necessary equipment before you start. You’ll need a sturdy stand to support the weight of the aquarium, as well as a hood or canopy to keep fish from jumping out. An efficient filtration system is vital to keep the water clean and healthy for your fish, so consider investing in a canister filter or power filter.

You’ll also need a heater to maintain a consistent water temperature, a thermometer to monitor it, and a water testing kit to ensure the water’s chemistry stays balanced. Don’t forget to add some substrate to the bottom of the tank, like sand or gravel, and some decorations, plants, and hiding spots for your fish to feel secure. By having all the necessary equipment prepared beforehand, you’ll ensure a smooth and successful setup for your 75-gallon aquarium.

how to fill 75 gallon aquarium


When it comes to water activities, having the right equipment is key to staying safe and comfortable. Whether you’re planning a day at the beach, going on a boating trip, or simply going for a swim, there are a few items that you should always have on hand. One essential piece of equipment is a life jacket or personal flotation device.

Even if you’re a strong swimmer, unexpected situations can occur in the water and having a flotation device can make all the difference. Another crucial item to have is proper footwear. Rocks, shells, and other sharp objects can be dangerous to walk on barefoot, so wearing water shoes or sandals can help protect your feet.

Additionally, a waterproof bag is great for storing your belongings and keeping them dry. Remember, when it comes to water activities, safety always comes first, so make sure you have the necessary equipment before diving in.


If you want to remove harmful chlorine from your aquarium water, a dechlorinator is a must-have tool. Before proceeding, make sure you have all the necessary equipment. To get started, you’ll need a water testing kit to confirm the presence of chlorine and other harmful chemicals.

A dechlorinator will not work if there are other harmful chemicals present in the water. Next, you’ll need to have the appropriate dechlorinator for your tank’s size, which you can find at your local pet store or online. Once you have all your equipment ready, you can proceed to the next step of the dechlorinating process.

Remember to follow the manufacturer’s instructions for optimal results. With a dechlorinator, you can give your aquatic pets a healthier and safer environment to thrive in.

Aquarium Thermometer

If you’re a fish enthusiast, then maintaining the correct temperature in your aquarium is crucial to your fish’s survival. It is important to note that different fish species require different water temperatures. Therefore, purchasing an aquarium thermometer is a wise investment that ensures your fish’s wellbeing.

Before purchasing a thermometer, ensure that you have all the necessary equipment, which includes a measuring cup or bowl, a thermometer, and a cleaning solution. The cleaning solution is especially crucial in ensuring the thermometer’s accuracy by keeping it free of any algae or debris. Additionally, ensure that the thermometer is submersible and can provide readings in both Celsius and Fahrenheit.

By gathering all the necessary equipment, you’ll be on your way to effectively monitor your aquarium’s temperature and ensure that your fish live a happy and healthy life.


Substrate When it comes to setting up a substrate for your aquarium, you’ll need to gather a few necessary pieces of equipment. First and foremost, you’ll want to choose the right type of substrate for your aquatic plants and fish. Gravel is a great option for most aquariums, as it allows water to flow freely and provides a stable base for plants to grow.

You’ll also need a siphon to clean the substrate regularly and remove any organic matter that has accumulated. A substrate rake can also come in handy for rearranging the substrate and planting new plants. It’s important to choose the right size and shape of substrate for your aquarium, as well as making sure it’s thoroughly rinsed before adding it to your tank to avoid cloudiness.

With the right equipment and substrate, you can create a healthy and thriving environment for your aquatic inhabitants.

Prepare the Aquarium

If you’ve just purchased a 75 gallon aquarium and are unsure about how to fill it, don’t panic! Preparing your new aquarium can be a fun and rewarding experience, and with some careful planning, it can be done in no time. First, make sure you have all the necessary equipment, such as a filter, heater, and lighting system, before filling the tank. Then, decide on the location of your aquarium, making sure it is level and stable before placing it.

Next, rinse your substrate thoroughly, and evenly spread it onto the bottom of the tank. Finally, fill your aquarium with water, using a dechlorinator to remove any toxins and prevent harm to your fish. Keep in mind, filling a large aquarium can take a while, so be patient and let the water condition for at least 24 hours before adding any fish.

With these simple steps, you’ll be on your way to creating a beautiful aquatic environment for your new finned friends.

Clean Aquarium

If you’re an aquarium enthusiast, you know how important it is to keep your tank clean and healthy for your fishy friends. While cleaning your aquarium may seem like a daunting task, it doesn’t have to be. The first step is to prepare your aquarium.

Remove all the decorations, plants, and rocks from the tank and set them aside. Next, use a net to remove any fish from the tank and place them in a temporary container. This way, you can clean the tank without harming your fish.

Drain the tank of all water and use an aquarium-safe cleaning solution to clean the glass and any remaining substrate. Once the tank is clean, rinse it thoroughly with water and reassemble the decorations. Fill the tank with fresh, dechlorinated water and add your fish back in once the temperature is stable.

By taking the time to properly prepare your aquarium for cleaning, you’ll ensure a clean and healthy environment for your aquatic buddies to thrive.

Add Substrate

Adding substrate to your aquarium is crucial for the survival of your aquatic plants and inhabitants. Before adding substrate, it’s important to prepare the aquarium by thoroughly cleaning it. Rinse the tank with warm water and gently scrub any algae or debris off the sides and bottom.

Once the tank is clean, consider adding a layer of aquarium soil or gravel to the bottom. This will provide a stable foundation for your aquatic plants to grow and will also help to anchor any decor or rocks in the tank. It’s important to choose a substrate that is appropriate for your specific aquarium setup.

Some substrates may be better suited for planted tanks, while others may be more suitable for a marine setup. Be sure to research and choose the right substrate for your tank before adding it. Once the substrate is added, fill the tank with water and start the filtration system.

It’s important to monitor the water quality to ensure that the substrate is properly cycling and that harmful toxins are not building up in the tank. By properly preparing the aquarium and adding the appropriate substrate, you can provide a healthy and thriving environment for your aquatic plants and inhabitants.

Install Necessary Equipment

Installing necessary equipment is a crucial step in setting up your aquarium. First, you will need to prepare the tank by cleaning it thoroughly. Next, add a layer of substrate to the bottom of the tank, which will serve as a base for your plants and decorations.

Once the substrate is in place, you can add your chosen plants and decorations, ensuring they are carefully placed to create a visually appealing environment for your fish. After decorating your aquarium, it’s time to add the essential equipment. You will need a heater to maintain the water temperature, a filter to keep the water clean, and a lighting system to promote plant growth.

Choosing the right equipment for your tank size and species of fish is essential for creating a safe and healthy environment for your aquatic pets. By installing the necessary equipment, you will ensure the longevity and well-being of your fish, plants, and other inhabitants. So, take your time and research the best equipment for your aquarium, and with proper care and maintenance, you will create a beautiful, thriving underwater ecosystem.

Fill the Aquarium with Water

The process of filling a 75-gallon aquarium with water can be a daunting task, but it doesn’t have to be a confusing one. First, ensure that the aquarium is clean by scrubbing it with warm water and soap, and rinsing thoroughly. Next, place a thick layer of substrate, such as gravel or sand, on the bottom of the tank to provide a foundation for the aquatic plants and decorations.

Once the substrate is in place, slowly add water to the tank, being careful not to damage any plants or disturb the substrate. If using tap water, it is important to treat it with a dechlorinator to remove any harmful chemicals before adding it to the tank. Once the water level has reached the desired height, it is time to install the filter, heater, lighting, and any other equipment needed for the aquarium.

Be sure to follow the manufacturer’s instructions and take the necessary precautions to ensure the safety of both the fish and the tank. With proper care and attention, a 75-gallon aquarium can become a thriving ecosystem for a variety of aquatic species.

Use a Dechlorinator

Before adding water to your aquarium, it’s essential to use a dechlorinator to remove any harmful chemicals present in the water. Chlorine and chloramine are commonly found in tap water, and they can harm your fish and other aquatic creatures. Dechlorinators work by neutralizing these chemicals, ensuring a safe environment for your pets.

Once you’ve treated the water with a dechlorinator, you can begin filling up your tank. But make sure you do it slowly and carefully as you don’t want to disturb the substrate or plants in your aquarium. It’s best to use a hose or bucket to add water gently and avoid any sudden movements that could affect the delicate ecosystem you’re trying to create.

Remember, every fish has its own specific needs, so check the water parameters regularly to ensure optimal conditions that will keep them happy and healthy.

Check Water Temperature

When filling your aquarium, it’s important to make sure the water temperature is just right. If the water is too hot or too cold, it can be detrimental to your fish and other aquatic creatures. To start, check the water temperature using a thermometer.

Most species of fish thrive in temperatures between 72 and 78 degrees Fahrenheit. You can adjust the temperature accordingly using a heater, but make sure to do so gradually to avoid causing stress to your fish. Additionally, consider using a water conditioner to remove any harmful chemicals or contaminants that may be present in your tap water before adding it to the aquarium.

By checking and adjusting the water temperature and using a water conditioner, you can create a healthy and comfortable environment for your aquatic pets to thrive in.

Start Filling Aquarium with Water Slowly

As your aquarium is ready to be filled with water, it’s important to do it slowly and carefully to avoid any mishaps or stress on your aquatic life. Start by adding some dechlorinated water to the bottom of your aquarium and then start filling it up slowly. Pour the water gently onto a plate or a plastic bag, which will help to diffuse the water flow and prevent any disturbance to the substrate or decorations.

Make sure to keep an eye on the water level and stop filling it up once it reaches the required level. It’s important to avoid over-filling the aquarium as it can lead to spillage and damage to your flooring. Once you have filled the aquarium with water, make sure to check the temperature and pH level to ensure that they are within the ideal range for your fish and plants to thrive.

Remember to take it slow and steady as it’s important for the freshwater ecosystem inside to adapt and adjust to the new environment gradually.

Test Water Parameters

When it comes to filling a 75-gallon aquarium, it’s important to also test the water parameters. This means checking things like the pH level, ammonia and nitrate levels, and water hardness. Depending on where you live, your tap water may be too hard or soft, which can greatly affect the health of your fish and the overall ecosystem in the tank.

To prevent any imbalances, it’s recommended to use a water conditioner before filling the tank. Once the tank is filled, take a sample of the water and test it with a test kit. This will give you an idea of the water’s current parameters and if any adjustments need to be made.

Remember, maintaining proper water parameters is crucial for the health and well-being of your aquatic pets.


Test water parameters is an important step to ensure the safety of drinking water. One aspect that should be included in testing is the nitrate level. Nitrate is a compound that is often found in fertilizers and can make its way into drinking water sources through runoff from agricultural areas or malfunctioning septic systems.

High levels of nitrate can be harmful to human health, particularly for infants and pregnant women. Nitrate consumption can lead to a condition called methemoglobinemia, which decreases the oxygen-carrying capacity of blood. Testing for nitrate in drinking water is simple, and home testing kits are available for purchase.

In addition, many water treatment facilities include nitrate testing as part of their regular testing and treatment process. Regular testing for nitrate levels can ensure that drinking water is safe and healthy for all to consume.


Nitrite is an important water parameter that aquarists need to regularly test to ensure the health and safety of their aquatic pets. Nitrite is a byproduct of the nitrogen cycle, which is the process of breaking down fish waste and other organic matter in the aquarium. High levels of nitrite can be toxic to fish, causing issues such as respiratory distress and even death.

By testing for nitrite, aquarium owners can catch any problems early and take the necessary steps to fix them. The easiest way to test for nitrite is to use a liquid test kit, which typically involves adding a few drops of a testing solution to a water sample and then comparing the color of the water to a color chart. It is recommended to test for nitrite at least once per week, especially in newly set-up aquariums or in tanks with a recent increase in fish population.

By staying on top of nitrite levels, aquarists can ensure a healthy and thriving aquatic environment for their fish.


Ammonia Water is essential to life, and we all need clean water to survive. To ensure the water is safe for consumption, its parameters need to be tested, and one of these parameters is ammonia. Ammonia is a colorless gas that is highly soluble in water.

It is a toxic element that can harm aquatic life and cause health problems in humans if consumed in large quantities. Therefore, it’s essential to keep ammonia levels under check to prevent any health hazards. The most common source of ammonia in water is from the decomposition of organic matter.

Additionally, ammonia also enters waterways from fertilizers and sewage. You can measure ammonia levels in water using a testing kit, and you should aim for levels below the safe threshold of 5 milligrams per liter.

Regularly testing water parameters will help identify any issues with quality, allowing you to take corrective measures before it’s too late. So, always ensure you keep an eye on ammonia levels and take action if you see a spike.


pH level, water test, acidity, alkalinity Do you know the pH level of your water? The pH level measures the acidity or alkalinity of your water, on a scale of 0 to 1 A pH of 7 is considered neutral, while higher pH values indicate alkalinity and lower pH values indicate acidity. Testing the pH of your water is important because it can affect the taste, health, and functionality of your plumbing systems.

When the pH level is too low, water can be corrosive and damage metal pipes. On the other hand, if the pH level is too high, it can lead to mineral buildup in your pipes and appliances. In addition, some people may be sensitive to pH imbalances, experiencing skin irritations or digestive issues.

To test your water pH level, you can use a simple kit or hire a professional. By understanding your water’s pH level, you can take appropriate measures to ensure it’s safe and healthy for you and your family.

Add Fish Slowly

When starting a new aquarium, it’s important to remember that patience is key, especially when it comes to adding new fish. To fill a 75 gallon aquarium, it’s best to add fish slowly, allowing the tank to establish its own ecosystem. Adding too many fish at once can result in an overwhelming amount of waste and lead to algae growth, which can be harmful to your fish.

Start by adding just a few fish at a time, monitoring their behavior and the water quality. Once the tank has adjusted and the water chemistry is stable, you can gradually increase the number of fish you add. Remember to research the species you plan to add, as different types of fish have different needs and may not be compatible with one another.

By taking your time and adding fish slowly, you can create a healthy and vibrant aquarium that your fish will thrive in.

Choose Right Fish

Choosing the right fish for your aquarium is crucial for a healthy and thriving aquatic environment. However, it’s important to remember to add fish slowly to avoid overloading the tank’s bio-load. Adding too many fish at once can cause a spike in ammonia and nitrite levels, which can be harmful to your fish and may even lead to their demise.

To ensure a proper aquarium set-up, it’s advisable to start with a few fish and gradually increase their numbers as the tank’s biological filtration system is established. This will create a stable environment for your fish to live and grow in. When selecting fish, it’s essential to consider their individual requirements, such as temperature, aquarium size, and compatibility with other fish in the tank.

It’s also important to choose fish that are suitable for the size of your aquarium. Some fish may grow too large for smaller tanks, while others require more space for proper swimming and movement. For example, goldfish are often mistakenly kept in small bowls, but they actually require a much larger aquarium to thrive.

Overall, adding fish to your aquarium is an exciting adventure, but it’s crucial to do so carefully and thoughtfully. By taking the time to select the right fish and adding them slowly, you can create a beautiful and healthy environment for your aquatic friends to call home.

Acclimate Fish to New Water

Acclimate Fish to New Water Adding fish to new water can be stressful for both the fish and the fish keeper. It is important to acclimate them slowly to their new environment to ensure the best chance for survival. One way to do this is by using the drip acclimation method.

Simply place the fish in a container and float the container in the new aquarium. Then, use airline tubing to siphon water from the aquarium to the container at a slow drip rate. This allows the fish to gradually adjust to the differences in water chemistry and temperature.

Another tip is to monitor the water parameters closely during the acclimation process. Make sure the pH, ammonia, nitrite, and nitrate levels are stable and within the appropriate range for the species of fish being introduced. It is also important to keep the lights off for the first few hours to reduce stress on the fish.

Remember, slow and steady wins the race when it comes to introducing new fish into an aquarium. Rushing the process can lead to a stressful and potentially deadly situation for all involved. Taking the time to properly acclimate your fish will increase their chances of survival and ensure a happy and healthy aquarium.

Add Fish Slowly to Avoid Shock

Adding new fish to your aquarium can be an exciting experience. But it’s important to do it slowly, to avoid shock and stress for both your new fish and the existing aquatic community. Introducing too many fish at once can lead to a dangerous spike in ammonia and nitrite levels, causing harm to your fish or even killing them.

A good rule of thumb is to add no more than one or two fish per week and monitor the water parameters closely. Make sure to acclimate your new fish slowly to their new environment by floating the bag in the aquarium for at least 20 minutes to equalize the temperature. This will help them adjust to the water conditions before they swim free.

By adding fish gradually, you’ll ensure a healthy and happy aquarium environment for your aquatic friends.

Maintain Aquarium Properly

Filling a 75-gallon aquarium can seem like a daunting task, but it’s essential to ensure the well-being of your fish. Before adding any water, it’s important to thoroughly clean the tank to remove any dirt or debris. Start by filling the tank with water, making sure there’s no chlorine present, which can be harmful to fish.

Adding a water conditioner or allowing the water to sit for a few days can help with removing chlorine. Then, carefully add substrate to the bottom of the tank. Be sure to rinse it off first to prevent cloudiness.

Next, it’s time to add any decorations, such as rocks or plants, and install any equipment, like filters and heaters. Finally, fill the rest of the tank with water and turn on all the equipment to ensure everything is working efficiently. Maintaining the aquarium means checking the water parameters regularly and performing water changes as necessary to keep the tank clean and healthy for your fish.

By following these steps, you can successfully fill and maintain your 75-gallon aquarium.

Regular Water Changes

Maintaining an aquarium can be a fun and rewarding activity. However, it is important to remember that maintaining a healthy and thriving aquarium requires regular care and attention. One of the most important aspects of keeping your aquarium in top condition is performing regular water changes.

This will help to ensure that the water in your aquarium stays clear and free from harmful chemicals and bacteria. It is recommended that you perform a water change of 10-15% of the total volume of water in your aquarium at least once a week. This will help to remove any built-up waste and debris that has accumulated in the water.

Additionally, it will help to replenish essential vitamins and minerals that your fish need to thrive. Remember to use a water conditioner to remove any chlorine or other harmful chemicals from tap water before adding it to your aquarium. By performing regular water changes, you can help to ensure that your aquarium remains healthy and beautiful for years to come.

Feed Fish Properly

Maintaining an aquarium can be a fun and rewarding experience, but it does require some effort and attention. One important aspect of keeping an aquarium is ensuring that the fish are fed properly. Overfeeding can lead to excess waste and poor water quality, while underfeeding can result in malnourished and unhealthy fish.

It’s important to research the specific dietary needs of your fish and provide them with a balanced and varied diet. This may include commercial fish food, live or frozen foods, or even vegetables. It’s also important to monitor how much and how often you feed your fish, adjusting as necessary to meet their needs.

With proper feeding, your fish will thrive and contribute to a beautiful and healthy aquarium environment.

Monitor Water Parameters

Maintaining an aquarium requires a lot of work, including monitoring water parameters to ensure a healthy environment for the fish. One of the most important factors to keep in check is the pH level of the water. Fish need a specific range of pH to thrive, and if it’s too high or too low, they can become stressed and even die.

Another important factor to monitor is the nitrate and ammonia levels in the water. These compounds can build up over time and become toxic to fish, causing illness or even death. To keep these levels in check, it’s important to perform regular water changes and use a quality water conditioner.

By staying on top of these parameters and keeping the aquarium clean and maintained, you can create a thriving environment for your fish to live in. Remember, a little extra effort on your part can go a long way in keeping your aquarium healthy and your fish happy.

Clean Aquarium Regularly

Maintaining a clean aquarium is essential for a healthy environment for your fish to thrive in. To keep your aquarium properly maintained, you should regularly clean it to remove any debris, excess food, and waste. A dirty aquarium can cause your fish to become stressed, sick, and even die.

You can start by cleaning the tank walls, the gravel, and the decorations using an aquarium vacuum. You should also change the water in the aquarium regularly and check for any signs of algae growth. A good practice is to only remove about a third of the water at a time during the water change to prevent any sudden changes in the water’s chemistry, which can stress the fish.

By following these maintenance steps, you can keep the aquarium clean and ensure the well-being of your aquatic pets.


In conclusion, filling a 75 gallon aquarium is no small feat! But with these tips and tricks, you’ll be able to create a vibrant underwater world for your aquatic pets. Remember to layer your substrate, add plants and rocks for structure, and fill with water slowly to prevent any mishaps. And if all else fails, just add a mermaid or two for a touch of whimsy.

Happy aquascaping!”


What are the necessary equipment needed to fill a 75-gallon aquarium?
To fill a 75-gallon aquarium, you will need a heater, filter, gravel, water testing kit, and decorations.

How much water will I need to fill a 75-gallon aquarium?
A 75-gallon aquarium will require approximately 75 gallons of water to fill.

How long should I wait before adding fish to a newly filled 75-gallon aquarium?
You should wait at least 24-48 hours before adding fish to a newly filled 75-gallon aquarium to allow the water to stabilize and the temperature to reach an adequate level.

What types of fish are suitable for a 75-gallon aquarium?
You can keep a wide variety of freshwater fish in a 75-gallon aquarium, including cichlids, angelfish, tetras, gouramis, and many others. Be sure to research the specific needs and compatibility of the fish you plan to keep.

How often should I clean a 75-gallon aquarium?
It’s recommended to clean a 75-gallon aquarium once a month, or more often if the water quality begins to decline. Regular water testing will help you determine when it’s time for a cleaning.

Can I use tap water to fill my 75-gallon aquarium?
Yes, you can use tap water to fill your 75-gallon aquarium, but it’s important to treat it with a water conditioner to neutralize any harmful chemicals like chlorine or chloramines.

How should I decorate my 75-gallon aquarium?
The decor of your 75-gallon aquarium is entirely up to you! Many people choose to add live or artificial plants, rocks, driftwood, or other ornaments to create a natural-looking environment for their fish. Just be sure to avoid anything that could harm your fish, such as sharp or toxic materials.