Aquarium Game

Aquarium Game is a cozy fish tank game where you build a freshwater aquarium from an empty glass box, cycle the water, stock it with community fish and keep every one of them happy. Happy fish earn coins to spend on plants, rocks, driftwood and other decor. Play it free in your browser on a computer, tablet or phone.

How to play

• Set up the tank: the Setup tab has 8 steps. Add gravel, fill with tap water and water conditioner, install the filter, heater (it holds 25 C) and light, then place a Java fern, a rock and some driftwood.
• Cycle the water: fish waste and old food make ammonia. Helpful bacteria that live in the filter turn ammonia into nitrite, and a second kind turns nitrite into nitrate. The meters above the tank show all three. With no fish yet, drop a pinch of food each day and let it rot so the bacteria have something to eat. When ammonia and nitrite fall back to 0, the tank is cycled.
• Add fish: the shop has 12 species: neon tetra, guppy, platy, corydoras, zebra danio, cherry barb, bristlenose pleco, betta, honey gourami, harlequin rasbora, otocinclus and cherry shrimp. Each entry shows its group size, temperature range and how much room it takes.
• Feed: pick the Feed tool and tap the water. Each tap drops a pinch of four pellets that slowly sink. Bottom dwellers like corydoras and shrimp pick up what lands on the gravel. Pellets that sit uneaten rot and add ammonia, so feed a little at a time.
• Clean: algae slowly grows on the glass while the light is on, faster when nitrate is high and slower when you have plants. Drag the Scraper across it to wipe it away. The Bucket button swaps 25% of the water, and the Water tab also offers 10% and 50% changes. Water changes lower nitrate but leave the bacteria alone, because they live in the filter.
• Decorate: buy decor in the Decor tab, then drag any piece along the gravel with the Decorate tool. Some decor unlocks as you finish goals.

Keeping fish happy

Pick the Look tool and tap a fish to see its happiness and what it needs. Happy fish earn coins over time. Unhappy ones turn pale and hide low near your decor. Fish care about:

• Clean water: any ammonia or nitrite stresses them, and nitrate above 40 ppm starts to bother them too.
• Temperature: most of these tropical fish need the heater. Without it the water settles near 21 C, which is too cool for neon tetras and bettas.
• Company: neon tetras, corydoras, zebra danios, cherry barbs, harlequin rasboras and otocinclus want a group of 6 or more. Guppies and platies like at least 3, and cherry shrimp do best in a colony of 5.
• Peaceful tankmates: only one betta fits in a tank. A betta may nip the long fins of guppies and may hunt cherry shrimp, so those pairings stress everyone involved.
• Food and space: hungry fish are unhappy, and so is an overcrowded tank.

Time only passes while the game is open. If you close it and come back, up to one minute of tank time catches up, so your fish never starve while you are away. The Speed button runs time five times faster, which helps while the tank cycles.

Goals

Ten goals guide a new tank: set it up, cycle the water, add your first fish, feed 10 times, do a water change, scrape the glass, keep a school of 6, have 5 species where every fish is happy, place 8 decorations, and have 12 happy fish at once. Each pays coins. Finish them all, then keep decorating or start a new tank. Your tank is saved in your browser.

Tips

• Plants use up some nitrate and slow algae, so a well planted tank needs fewer water changes.
• Bristlenose plecos, otocinclus and cherry shrimp graze algae and help keep the glass clean.

FAQ

Can my fish die?

No. Fish in this game never die. If the water goes bad, they turn pale and hide until you fix it, then they perk up again.

Does it work on phones?

Yes. Tap the water to feed and drag on the glass to scrape. Dragging in the tank does not scroll the page.

Is the fish care in the game realistic?

It is simplified but follows the real basics: the nitrogen cycle, schooling fish needing groups, one betta per tank, not overfeeding and regular water changes. Real tanks take weeks to cycle, while the game speeds that up to a few minutes.

Like relaxing water games? Try Fishing to cast for twelve species across a day and night cycle, or design a flower garden in the Garden Game.