REEF KEEPERS LOSE CORALS AND FISH TO INCOMPATIBLE TANK MATES — EVERY YEAR

Will your tank survive this fish?
Find out before you buy.

Most fish deaths in home reefs are preventable. AquaHarmony checks every species against your tank — water volume, existing livestock, coral, flow rate — before you bring anything home.

10+ reef keepers
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Start Free — No Card NeededBrowse Species
Tank Score71 / 100
Ocellaris Clownfish90
Firefish Goby88
Yellow Tang58
Lionfish35
OverallNeeds Attention
Compatibility Check
Blue Tang87/100
Six-Line Wrasse82/100
Yellow Belly Hippo Tang61/100
Why it scored this

Large tangs need 180+ gallons. Your 90gal may cause stress and aggression with existing fish.

Peaceful with existing livestock
How it works

Three steps to a healthier tank

1
Add your tank

Enter your tank size, water volume, flow rate, and existing livestock. Takes about 2 minutes.

2
Search any species

Type any reef fish, coral, or invert. Get an instant compatibility score against your specific setup.

3
Know before you buy

Every score comes with plain-language explanations — aggression risk, bioload impact, coral compatibility.

Built for reef keepers

Everything you need to keep your tank thriving

Species Database

Browse 900+ reef-safe species. Every entry scored across aggression, bioload, coral safety, and more.

Compatibility Solver

Check any species combination against your tank before you buy. No more second-guessing at the fish store.

Pest Identification

Identify and solve common reef pests — aptasia, flatworms, parasitic copepods — with recommended treatments.

From reef keepers

What reef keepers are saying

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Frequently asked questions

How does AquaHarmony check if a fish is compatible with my tank?
AquaHarmony scores every species against your specific tank parameters — water volume, flow rate, existing livestock, and coral load. Each score ranges from 0–100 and includes plain-language explanations for every factor that drove the score.
Is my fish compatible with my coral?
Yes. AquaHarmony tracks coral compatibility as a separate dimension in every score. Some fish species — certain angels, butterflies, and puffers — are known coral threats. We flag these specifically so you know before you buy.
Can I check compatibility before buying a new fish?
Absolutely. That's the core use case. Search any species, enter your tank details, and get an instant score with reasoning. You can do this on the free plan before you commit to adding anything to your tank.
Does AquaHarmony work for freshwater aquariums?
Currently focused on reef aquariums only. Freshwater compatibility checking is in active development — sign up and we'll notify you when it's ready.
How many species are in the database?
Currently covering 900+ reef-safe species — fish, corals, inverts, and crustaceans. Species data is updated regularly as new research and hobbyist reports come in.

Stop guessing.
Start thriving.

Join 10+ reef keepers who caught compatibility problems before they became expensive.

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