PZ2 GuideIndependent Planet Zoo 2 fan guide

Planet Zoo 2 aquarium guide: build, filter and stock a tank

Frontier's player guides and Zoopedia, read 20 October 2026

By Rai Ansar · Checked against the linked official sources on · How this page was made

37 aquarium species, three salinities, one filter per 500 m²

To build an aquarium in Planet Zoo 2, pick Aquarium in the Habitat Barrier tool, draw the tank, then place an Aquarium Staff Gate: the tank fills with freshwater. Connect the gate to a filtration network to switch it to brackish or saltwater and keep it clean. One water filter cleans up to 500 m² of water, and the filters need power. Frontier's Zoopedia lists 37 aquarium species: 35 fish, sharks and rays, plus the Hawksbill Turtle and West Indian Manatee.

What this page adds

Frontier explains aquariums in its player guides and lists each species on a separate Zoopedia page. We read all 37 aquarium species pages and put them side by side: which salinity each accepts, the temperature bands that rule out mixing, how much water each needs, and which species the Zoopedia says can share a tank.

How to build an aquarium, step by step

  1. Draw the tank. Open the Habitat Barrier tool, choose Aquarium (aquarium barriers have their own section of the Barrier menu) and draw the walls with the Line or Curve tool.
  2. Add an Aquarium Staff Gate. The space fills with water by itself. Staff enter the water in diving suits, so the gate can sit above the ground.
  3. Connect filtration. Place a Water Filter from Facilities, Utilities, then use Edit Filtration Network to run a pipe from the node on the staff gate to the filter. The network sets the salinity: freshwater, brackish or saltwater.
  4. Give it power. Filters only work near a power source. Eco-friendly power costs more to build, has no running costs and adds to your Sustainability Rating.
  5. Furnish it. Add feeders, nests and enrichment from the Aquarium tab of the Browser, then aquatic plants, scenery and terrain for each species' environment needs.
  6. Move the animals in and assign staff. Bring the animals from Animal Storage, send in a keeper, and leave a path so mechanics can reach the filters.

Salinity: which species need freshwater, brackish or saltwater

Every aquarium species accepts one or more salinities, and the wrong water can kill: Frontier's building guide says aquarium animals in water of the wrong salinity risk dying of osmotic stress. 24 of the 37 species accept saltwater only and 7 accept freshwater only. The West Indian Manatee accepts any salinity. A species can appear in more than one column below.

Freshwater 9 species
  • An African tigerfish swimming over sunken branches in an aquarium African Tigerfish
  • A blunthead cichlid with a dark head and a red-flushed body Blunthead Cichlid
  • A Boeseman's rainbowfish with a blue head and an orange tail Boeseman's Rainbowfish
  • A brown trout with dark spots swimming over pale gravel Brown Trout
  • A clown loach with orange and black bands Clown Loach
  • A common rudd with red fins swimming near the surface Common Rudd
  • A pale giant gourami swimming in an aquarium Giant Gourami
  • Koi with white, orange and black markings swimming in an aquarium Koi
  • A West Indian manatee feeding on plants underwater West Indian Manatee
Brackish 6 species
  • A pale giant gourami swimming in an aquarium Giant Gourami
  • A young giant grouper with yellow and black blotches Giant Grouper
  • A hawksbill turtle swimming over a sandy seabed Hawksbill Turtle
  • An Oman cownose ray, a close relative of the Javanese cownose ray, swimming in blue water Javanese Cownose Ray
  • A school of Pacific sardines swimming together Pacific Sardine
  • A West Indian manatee feeding on plants underwater West Indian Manatee
Saltwater 29 species
  • A blackspotted puffer swimming beside coral Blackspotted Puffer
  • A blacktip reef shark swimming just below the water surface Blacktip Reef Shark
  • A school of blue and gold fusiliers over a dark reef Blue and Gold Fusilier
  • A bluespine unicornfish swimming over coral Bluespine Unicornfish
  • A clown anemonefish among the tentacles of an anemone Clown Anemonefish
  • A clown triggerfish with white spots on a dark body Clown Triggerfish
  • A dolphinfish swimming in a blue aquarium Dolphinfish
  • A young giant grouper with yellow and black blotches Giant Grouper
  • A golden trevally with dark bars swimming past coral Golden Trevally
  • A great hammerhead shark swimming in an aquarium Great Hammerhead
  • A hawksbill turtle swimming over a sandy seabed Hawksbill Turtle
  • A humphead wrasse with a bulging forehead in blue water Humphead Wrasse
  • An Indian Ocean oriental sweetlips with black and white stripes and yellow fins Indian Ocean Oriental Sweetlips
  • An Indo-Pacific leopard shark with a pale, spotted body Indo-Pacific Leopard Shark
  • An Indo-Pacific sergeant with black bars and a yellow back Indo-Pacific Sergeant
  • An Oman cownose ray, a close relative of the Javanese cownose ray, swimming in blue water Javanese Cownose Ray
  • A longfin batfish with a tall, rounded body swimming near rocks Longfin Batfish
  • An ocean sunfish swimming in a large aquarium tank Ocean Sunfish
  • An ocellated eagle ray gliding through blue water Ocellated Eagle Ray
  • A Pacific bluefin tuna swimming past visitors in a large aquarium tank Pacific Bluefin Tuna
  • A school of Pacific sardines swimming together Pacific Sardine
  • A palette surgeonfish with a royal blue body and a yellow tail Palette Surgeonfish
  • A red lionfish with spread, striped fins in open water Red Lionfish
  • A sailfin snapper with blue and yellow stripes swimming past coral Sailfin Snapper
  • A sand tiger shark with ragged teeth swimming past a reef Sand Tiger Shark
  • A school of bannerfish with black and white bands swimming over a reef Schooling Bannerfish
  • A black threespot damselfish with a white spot on its side Threespot Damselfish
  • A West Indian manatee feeding on plants underwater West Indian Manatee
  • A bright yellow tang against a black background Yellow Tang

Photos from Wikimedia Commons; authors and licences are on the credits page.

Salinity belongs to the filtration network, not to the tank. Change the network's setting and every tank and pond connected to it changes too, so a saltwater reef and a freshwater koi tank need separate networks. A Water Pump on a network also changes the salinity of the habitat water it serves, and land animals only drink from freshwater.

Water temperature: why some fish can never share a tank

Each species has a temperature band, and welfare drops outside it. The Ocean Sunfish tolerates the coldest water (10 to 25 °C). The Brown Trout (12 to 19 °C) and the Clown Loach (25 to 30 °C) share no temperature at all. If the staff gate has power, you can set the tank's temperature in the Environment tab of its Info Panel. The bigger the gap between that setting and the weather, the more the tank costs to run.

  • Ocean Sunfish 10 to 25 °C
  • Brown Trout 12 to 19 °C
  • Pacific Sardine 15 to 26 °C
  • Sand Tiger Shark 16 to 28 °C
  • Pacific Bluefin Tuna 17 to 26 °C
  • Common Rudd 18 to 24 °C
  • Koi 18 to 25 °C
  • Great Hammerhead 20 to 28 °C
  • Blue and Gold Fusilier 21 to 31 °C
  • Blacktip Reef Shark 22 to 28 °C
  • Longfin Batfish 22 to 28 °C
  • Red Lionfish 22 to 28 °C
  • Sailfin Snapper 22 to 29 °C
  • African Tigerfish 22 to 30 °C
  • Hawksbill Turtle 22 to 30 °C
  • Humphead Wrasse 22 to 30 °C
  • Blackspotted Puffer 23 to 27 °C
  • Palette Surgeonfish 23 to 28 °C
  • Clown Triggerfish 23 to 30 °C
  • West Indian Manatee 23 to 30 °C
  • Blunthead Cichlid 24 to 27 °C
  • Ocellated Eagle Ray 24 to 27 °C
  • Clown Anemonefish 24 to 28 °C
  • Dolphinfish 24 to 28 °C
  • Giant Gourami 24 to 28 °C
  • Indian Ocean Oriental Sweetlips 24 to 28 °C
  • Indo-Pacific Sergeant 24 to 28 °C
  • Schooling Bannerfish 24 to 28 °C
  • Threespot Damselfish 24 to 28 °C
  • Yellow Tang 24 to 28 °C
  • Bluespine Unicornfish 24 to 29 °C
  • Giant Grouper 24 to 29 °C
  • Indo-Pacific Leopard Shark 24 to 29 °C
  • Golden Trevally 24 to 30 °C
  • Javanese Cownose Ray 24 to 30 °C
  • Boeseman's Rainbowfish 25 to 28 °C
  • Clown Loach 25 to 30 °C
Temperature bands from Frontier's Zoopedia, read 20 October 2026. Bar colour shows salinity: freshwater freshwater or brackish brackish or saltwater saltwater any. The warmest floor is 25 °C (Boeseman's Rainbowfish and Clown Loach).

Tankmate finder

Pick a species and how many you plan to keep. You get the water it needs, a filter count from Frontier's 500 m² figure, and every partner its Zoopedia page lists, with the salinity and temperature the two share. It runs in your browser and sends nothing.

Turn on JavaScript to use the finder. The full table is on the animal requirements page.

Filtration and clean water

Maintenance, leaks and editing a tank

A hawksbill turtle swimming over a sandy seabed
Photo: B.navez, CC BY-SA 3.0

Leaks. Aquarium barriers wear down and show cracks. Mechanics service them at regular intervals; let condition fall too far and the barrier leaks. Guests walking near a leak run away, and an inspector who spots one ends the inspection and fines you. Assign staff to the area so repairs happen in time.

Editing. You cannot reshape a tank with water or animals in it. Box the animals first, press Drain Water below the aquarium's Info Panel, change the wall height or lower the terrain with the Barrier tool, then refill. Update 1.0.5 fixed fish getting stuck outside a tank when the habitat was moved, and shoals now use extra space when a tank grows.

Shoals. Many fish are managed as a shoal, not as individuals. A shoal with good welfare grows to a maximum, then part of it splits off as a new shoal; contraception stops the split. A shoal with poor welfare shrinks until it dies out. Shoals have no genetics to manage, though some species, such as the Koi, have colour morphs.

Aquarium fixes since launch

The four species above need the most deep water for one animal: Great Hammerhead 960 m², Sand Tiger Shark 420 m², Dolphinfish 400 m² and Ocean Sunfish 300 m². 16 aquarium species can also live in an exhibit instead. For every aquarium species in one sortable table, with deep water per extra animal and group size, see the animal requirements page; its calculator plans the space for any group. For biomes and regions, see the Planet Zoo 2 fish list.

Common questions

How do you build an aquarium in Planet Zoo 2?

Open the Habitat Barrier tool and choose Aquarium, then draw the tank with the Line or Curve tool. Place an Aquarium Staff Gate and the tank fills with water, freshwater by default. Connect the gate to a filtration network to set the salinity and keep the water clean, then add feeders, nests and enrichment from the Aquarium tab of the Browser.

How do I change the salinity of an aquarium?

Through the filtration network connected to the tank. In Edit Filtration Network you set the network to Freshwater, Brackish or Saltwater, and every body of water on that network changes with it. Freshwater and saltwater tanks therefore need separate networks.

How many water filters does an aquarium need?

Frontier's Aquariums guide says one water filter cleans up to 500 m² of water, so a bigger tank needs more than one. Demand also rises with the number of animals. If the network's filtration rate stays below the tank's demand, water cleanliness falls.

Why is my aquarium leaking?

Aquarium barriers lose condition over time. Mechanics have to service them, and when condition gets too low the barrier starts to leak. Guests flee from leaks, and an inspector who finds one ends the inspection with a fine.

How do I edit or resize an aquarium?

Empty it first. Box up the animals, then use the Drain Water button below the aquarium's Info Panel. Once the tank is empty you can change the wall height or lower the terrain with the Barrier tool, then add the water back. Since Update 1.0.5 (16 October 2026), shoals use the new space when you enlarge a tank.

How many aquarium animals are in Planet Zoo 2?

37, according to Frontier's Zoopedia on 20 October 2026: 35 fish, sharks and rays, plus the Hawksbill Turtle and West Indian Manatee. Three of them (Blue and Gold Fusilier, Great Hammerhead and Longfin Batfish) come only with the Deluxe Edition.

Which aquarium animals can live together?

Each Zoopedia page lists "thriving" and "neutral" partners. Four species (Humphead Wrasse, Indo-Pacific Leopard Shark, Javanese Cownose Ray and Ocellated Eagle Ray) each list 11 thriving partners. The African Tigerfish, Brown Trout, Great Hammerhead and West Indian Manatee list no partners at all. The tankmate finder on this page shows each species' list with the salinity and temperature they share.

More Planet Zoo 2 guides

Sources

Each source was opened and checked on 20 October 2026. Frontier's own pages are the authority; if they change, they take precedence over this page.

  1. Frontier player guide, "Aquariums": building an aquarium, staff gates, freshwater default, editing and draining, temperature and running costs, barrier condition and leaks, filtration, one water filter per 500 m², water and tank cleanliness
  2. Frontier player guide, "Building Your Zoo": filtration buildings and networks, pipes from the aquarium node, salinity per network, water pumps, osmotic stress, power facilities
  3. Frontier player guide, "Animals": aquatic species and aquariums, shoals, cleaning and disease
  4. Frontier, Planet Zoo 2 Zoopedia: the 37 aquarium species pages: salinity, temperature, deep-water area, preferred group and thriving and neutral partners, read 20 October 2026
  5. Frontier, "Planet Zoo 2 - Update 1.0.4" (14 October 2026): shoal welfare, shoal info panels, dead shoals, juvenile shoal trading
  6. Frontier, "Planet Zoo 2 - Update 1.0.5" (16 October 2026): fish stuck outside a moved aquarium, shoals and enlarged aquariums, vets and dead animals in aquariums
  7. Frontier, Steam announcement "Under Investigation" (20 October 2026): fixes being tested: aquarium forage trays, boxing when editing aquariums, shoal animations