Build Ideas · Interiors · Java & Bedrock

How to Build an Aquarium

A glass wall of water, lit from above, with fish, coral and kelp inside. One of the best interior features you can build.

Frame the glass. An aquarium is a glass box set into a wall or stand. Build the frame first, then water sits behind clean glass.
Light from above. Sea lanterns or glowstone over the tank give that bright, watery glow and real caustics.
Fill it with life. Sand, coral, kelp and a few fish turn a water box into a living tank.

What you need

dark prismarine

Tank frame

glass

Viewing wall

water still

The water

sea lantern

Overhead light

sand

Reef floor

tube coral fan

Colour + coral

Build it in five

Build the box

Frame a watertight box of your size in prismarine, deepslate or stone, with the viewing side left open. Bigger is better; a wall-height tank looks stunning.

Add the glass

Glaze the open side with glass or a glass-pane wall and keep the frame around it, so it reads as a built-in tank and not a floating cube of water.

Fill with water

Source-block it from the top layer so the water stays still, and waterlog stairs and slabs to shape edges. Light it from above with sea lanterns.

Build the reef

Lay sand or gravel, plant kelp and seagrass, and dot coral blocks and fans for colour. Add a rock or two and a small sunken detail.

Add the life

Bucket in fish (cod, salmon, tropical fish), an axolotl or a turtle, then frame the whole thing so the room points straight at it.

Glass, light, and something moving

A tank of still blue water is a swimming pool. What makes an aquarium is the glass front, bright light from above, and life inside: kelp drifting, coral colour, a fish or two crossing the glass. Build the box, then spend your time on what is inside it.

Quick answers

How do you build an aquarium in Minecraft?

Frame a watertight box with a glass front, fill it with source water from the top so it stays still, light it from above with sea lanterns, then add sand, kelp, coral and fish. Keep a frame around the glass so it reads as built-in.

How do I keep the water still?

Place water source blocks across the whole top layer so every block becomes a source, or fill the top row last. Waterlogging stairs, slabs and glass panes lets you shape edges without flowing water.

What fish can I put in a tank?

Cod, salmon, pufferfish and tropical fish from buckets, plus axolotls, turtles, dolphins and squid in bigger tanks. They swim freely in water that is deep enough, so build it at least three or four blocks deep.

How do I light an aquarium?

Sea lanterns or glowstone above or behind the tank give the bright underwater look and cast caustics. Hide the source in the frame or ceiling so you see the glow, not the block.

How big should an aquarium be?

Anything from a small 3x3 window tank to a full wall or room divider. Deeper tanks of four blocks and up hold fish better and look more dramatic; a wall-height tank is a real showpiece.

Does this work the same on Bedrock?

Yes. Water mechanics, glass, sea lanterns, coral and fish buckets work the same on Java and Bedrock, so the aquarium builds identically on either edition.