Underglass app icon: an orange betta fish above a glass tank

Plan your tank in 3D before you spend a cent.

Shape the substrate, place stone and driftwood, plant a carpet, add a school of fish, then orbit the tank and see how it looks.

Download on the App StoreFree to start. Rare items cost coins, no subscription.
Underglass on iPhone: a planted 3D aquarium with stone, plants and a school of fish
Works offlineNo internet needed to design.
No account, no adsYour tanks stay on your device.
Free to startBegin with 100 coins, earn 10 more each day.
No subscriptionCoins are one-time packs and never expire.
Placing a stone in a 3D tank, with a choice of stones below
Design in 3D

Shape the floor, then plant it

Sculpt hills and valleys into the substrate with a brush. Place stone, driftwood and decor, then plant stems, carpets and rosettes where you want them. Pick a tank from a small nano cube to a 180 cm display tank.

The Summary panel showing volume, fish count and a compatibility check
Know what will work

Check it before you buy it

Fish swim in schools and keep to their own water level. The Summary panel warns you about fish that do not belong together and shows when the tank is getting crowded. More than 140 fish, plants, stones and decor items come with notes.

The Examples list with sample tanks
Start fast, keep going

Begin from 21 sample layouts

Start from an example or an empty tank. Save a photo or a 10 second video of your tank, or send the tank file to a friend. Your Living tank grows plants over real days, even when the app is closed, and widgets show how it is doing.

The Coin Shop with a 100 coin balance
Fair coins

No ads, no gacha, no weekly plan

Common species, plants and decor are free. Rare fish, color strains and large tanks cost coins. Coins come in one-time packs, never expire and are not a subscription. What you unlock is yours for good.

Underglass is a design tool. Always check the needs of real fish and plants before you buy them.