Make an underwater house with @LuMo - Fun at-home activities for Kids.

All Activities

Make an underwater house with @LuMo

Build a miniature underwater house with @LuMo using a clear jar, waterproof toys, colored sand, fake plants, and sealed water to explore habitat design.

Table of contents

Step-by-step guide to make an underwater house with @LuMo

What you need

Clear jar with lid, waterproof toys (plastic only), colored sand, small fake plants, clean water, funnel or spoon, waterproof clear sealant or strong waterproof tape, waterproof stickers or marker, adult supervision required

Step 1

Gather all materials and put them on a clean table so your workspace is ready.

Step 2

Wash and dry the clear jar and the waterproof toys to make sure everything is clean.

Step 3

Use the funnel or spoon to pour colored sand into the jar to make a colorful base about one to two inches deep.

Step 4

Press small wells or hills into the sand where you want to place plants or little rooms.

Step 5

Push the small fake plants into the wells to anchor them in the sand and create underwater foliage.

Step 6

Place the waterproof toys and tiny house pieces into the sand to build your mini underwater neighborhood with @LuMo.

Step 7

Slowly pour clean water into the jar until it is nearly full while leaving a small air gap at the top to prevent overflow.

Step 8

Screw the lid on tightly and wipe any water from the outside of the jar.

Step 9

Ask an adult to apply waterproof sealant or strong tape around the lid and let it dry so your house stays sealed and leakproof.

Step 10

Share your finished underwater house with @LuMo on DIY.org and tell everyone about your habitat design.

Help!?

What can I use instead of colored sand or small fake plants if I can't find them?

Use aquarium gravel, dyed rice, or craft beads in place of colored sand and small plastic seaweed or cut paper plants instead of fake plants when you pour the base and push plants into wells.

What should I do if water seeps out after I screw the lid on?

Unscrew the lid, dry the rim and threads, re-tighten it, then follow the instructions to have an adult apply waterproof sealant or strong tape around the lid and let it fully cure before filling again.

How can I adapt the activity for different ages?

For younger children have an adult wash the jar and pre-pour the colored sand and anchor the plants so the child can place toys, while older kids can press detailed wells, arrange tiny house pieces, and experiment with layered sand colors.

How can we make the underwater house more special or long-lasting?

Personalize it by adding glow-in-the-dark paint to tiny house pieces, include a small waterproof LED before screwing the lid, and finish by sharing your habitat design with @LuMo on DIY.org as suggested.

Watch videos on how to make an underwater house with @LuMo

0:00/0:00

Here at SafeTube, we're on a mission to create a safer and more delightful internet. 😊

Minecraft House Tutorial: How to Build the Ultimate Underwater Base

4 Videos

Facts about aquatic habitat design for kids

🐠 Bottle dioramas and jar aquariums have been made for centuries as tiny, contained worlds to explore.

🌊 Freshwater jar projects are easier for kids than saltwater ones because ocean chemistry is more complicated.

🪴 Live aquatic plants produce oxygen during the day, helping keep small sealed habitats healthy.

🧴 Use only waterproof, non-toxic toys and seal lids tightly — some plastics and glues can contaminate water.

🏠 Building an underwater house is a form of diorama-making—miniatures plus sand, plants, and creativity!

How do I make an underwater house with @LuMo?

Start with a clean clear jar and a tight lid. Add a layer of colored sand, then use tweezers to arrange fake plants and waterproof toys, placing the @LuMo figure where you want the house to be. Slowly fill the jar with distilled water using a funnel to reduce bubbles. Wipe any spills, close the lid, and have an adult seal the rim with clear silicone or hot glue. Let the seal fully cure before handling.

What materials do I need to make an underwater house with @LuMo?

You’ll need a clear jar with a tight lid (plastic or glass), a small waterproof @LuMo toy or figure, colored sand or aquarium gravel, fake aquarium plants, distilled or cooled boiled water, a funnel, tweezers, paper towels and clear silicone sealant or hot glue for sealing. Optional items: clear epoxy resin for a permanent display, small LED light, and non-toxic decorations. Choose nonbreakable containers for younger children.

What ages is the underwater jar house activity suitable for?

This craft is best for children aged about 5 and up with adult help. Kids 5–7 can layer sand and place plants and toys while an adult handles sealing and any hot tools. Ages 8–12 can do more of the assembly with supervision. Avoid giving small parts or glass jars to children under 3 because of choking and breakage risks. Always supervise when using adhesives, hot glue, or resin.

What are the benefits and safety tips for the underwater house activity?

Making an underwater house encourages creativity, fine motor skills, and basic habitat-design thinking—great for storytelling and simple STEM talks. For safety, use non-toxic, waterproof toys, avoid tiny parts for toddlers, and prefer plastic jars for young children. Adults should apply sealant, hot glue or resin and test for leaks. Variations include a dry sand-only version, LED lighting, or using clear resin instead of water for a permanent scene.

Ready to create?