The Basic Steps to Build a Minecraft Aquarium
A Minecraft aquarium is a water-filled structure that holds fish and displays them behind glass or other transparent blocks. You build it by creating a container, filling it with water, adding fish, and viewing it through transparent walls. The simplest aquarium takes about 10 to 15 minutes to build and requires only water, glass, and fish caught from the ocean or rivers.
The fastest way to start is to dig a hole at least 2 blocks deep and 3 blocks wide, line it with glass on the sides and front, fill it with water using a bucket, then catch fish with a bucket and place them inside. Fish in Minecraft include tropical fish, pufferfish, salmon, and cod — each swims differently and looks distinct, so mixing types makes the aquarium more interesting to watch.
Key Takeaways
- Build the container first by digging or stacking blocks, then line the inside with glass or other transparent blocks so you can see the fish.
- Fill the container with water using a water bucket, which you can obtain by right-clicking a water source with an empty bucket.
- Catch fish by holding a bucket and right-clicking on them in the ocean, river, or any water source — they will go into the bucket as items.
- Place fish inside your aquarium by right-clicking with the bucket containing the fish, and they will swim out into the water.
- Add decorations like sand, gravel, seaweed, or coral to make the aquarium look more natural and give fish places to hide.
Choosing a Location and Container Size
Pick a spot where you want to watch your fish regularly — near your base, in a living room, or along a hallway. The location matters because you will be looking at the aquarium often, so place it somewhere you pass through or spend time.
Container size depends on how many fish you want and how much detail you plan to add. A small aquarium can be as small as 3 blocks wide, 3 blocks tall, and 2 blocks deep — this holds 4 to 6 fish comfortably. A medium aquarium might be 5 blocks wide, 4 blocks tall, and 3 blocks deep, holding 10 to 15 fish. Larger aquariums look more impressive but take longer to fill and decorate. Start small if this is your first one; you can always build a bigger one later.
Building the Container and Adding Glass
Dig out the space for your aquarium or build walls using any solid block — stone, dirt, wood, or concrete all work. The key is making sure the inside is hollow and ready to hold water. If you dig, make sure the bottom is flat so water spreads evenly. If you build walls, stack blocks to the height you want, then hollow out the inside.
Line the inside with glass blocks on all sides except the back, or use glass on the front and sides only if you want to save materials. Place glass by right-clicking on the container walls from the inside. Transparent blocks like glass panes, tinted glass, or dark prismarine also work and let you see the fish clearly. Leave at least one side open or use a different block for the back wall so you have a place to add water without it flowing out.
Make sure there are no gaps between glass blocks, or water will leak out. If you see water flowing through cracks, add more glass or seal the gap with a solid block from the outside.
Filling the Aquarium with Water
Obtain a water bucket by finding any water source — ocean, river, lake, or rain — and right-clicking on it with an empty bucket in your hand. The bucket will fill with water and you can carry it in your inventory.
Pour the water into your aquarium by right-clicking inside the container. If your aquarium is small, one bucket may fill it completely. Larger aquariums need multiple buckets. Pour water from the highest point so it flows down and fills evenly. Wait a few seconds after pouring each bucket so the water settles before adding more.
Check that the water level reaches near the top but does not overflow out of the container. If it does overflow, dig a small drain channel outside the aquarium or add a solid block to stop the flow. Once the water is at the right level, you are ready to add fish.
Catching and Placing Fish
Fish spawn naturally in ocean biomes, rivers, and any water source in Minecraft. To catch a fish, hold an empty bucket and right-click on the fish in the water. The fish will disappear and go into your bucket as an item. You can carry multiple fish buckets in your inventory at once.
Different fish types behave differently: cod and salmon are common in oceans and rivers, tropical fish come in many colors and patterns and spawn in warm ocean biomes, and pufferfish spawn in warm oceans and puff up when threatened. Catching a mix of types makes the aquarium more visually interesting.
To place a fish in your aquarium, hold the bucket containing the fish and right-click inside the water. The fish will swim out into the aquarium. Repeat this for each fish you want to display. Fish will swim around the aquarium and stay alive as long as the water is there — they do not need food and will not die from age.
Adding Decorations and Details
Decorations make an aquarium look more like a real underwater environment and give fish places to explore. Sand and gravel on the bottom are the easiest additions — place them by right-clicking inside the aquarium. Seagrass, kelp, and sea pickles add vertical interest and movement. Coral blocks in various colors (brain coral, bubble coral, fire coral, horn coral, and tube coral) create colorful structures fish can swim around.
Avoid decorations that are too large or block the view of the fish. Leave open space in the middle so fish have room to swim and you can see them clearly. Dark blocks like blackstone or dark prismarine behind the aquarium make the fish stand out more against the background.
Lighting helps too — place glow berries, lanterns, or sea lanterns near or inside the aquarium so the fish are well-lit and straightforward to see. Avoid placing light sources directly in front of the glass, as they can create glare.
Common Mistakes to Avoid
The most common mistake is leaving gaps in the glass or container walls, which causes water to leak out and the fish to escape. Before adding water, walk around the outside of your aquarium and check every seam. If you see water dripping, add another glass block or seal it from the outside.
Another mistake is making the aquarium too small for the number of fish you want. Fish do not take up space the way they do in real life, but a crowded aquarium looks cluttered and is harder to see into. Aim for 4 to 6 fish per small aquarium, 10 to 15 per medium one.
Do not fill the aquarium completely to the top — leave at least one block of air space at the top so fish can breathe and water does not spill over when you place decorations or catch fish. Also avoid placing solid blocks directly in front of the glass, as they block the view of the fish inside.
Frequently Asked Questions
Do fish in Minecraft need food or care?
No. Fish in Minecraft do not need food, oxygen, or any maintenance. They will live indefinitely in water as long as the water source remains. You only need to keep the water in the aquarium and make sure the container does not break.
Can I use other blocks instead of glass to see the fish?
Yes. Glass panes, tinted glass, dark prismarine, and any transparent or semi-transparent block works. Tinted glass is darker and makes fish stand out more. Experiment with different blocks to find the look you prefer.
What happens if a fish escapes or dies?
Fish do not die in Minecraft. If a fish escapes because of a leak, it will swim away in the nearest water source. Patch the leak with glass and catch another fish to replace it using a bucket.
Can I breed fish in an aquarium?
No. Fish cannot breed in Minecraft. You can only place them in water using a bucket. If you want more fish, you must catch them from the wild and bring them to your aquarium.
How do I move an aquarium to a different location?
Break the glass blocks and let the water flow out, then catch all the fish with buckets and carry them to the new location. Rebuild the aquarium in the new spot and place the fish back inside. This takes longer than building a new one, so consider building your aquarium in a permanent location from the start.