Free Aquarium Tool By SpawnOS

Fish Compatibility Checker for smarter community tanks.

The SpawnOS Fish Compatibility Checker helps aquarists compare fish, shrimp, snails, axolotls, live foods, and microfauna before mixing them in the same aquarium. Built by Blackwater Aquatics Canada, it looks beyond basic water parameters and analyzes behavior, predation risk, temperature, habitat, flow, tank setup, and whether two animals are true tankmates — or actually predator and prey.

Fish Compatibility Calculator Tankmate Intelligence Predator / Prey Detection Freshwater Aquarium Planning
Use The Free Calculator How It Works
Betta Fish × Daphnia Live Food
25
Not a true tankmate pairing. Daphnia are live food and may be useful as feeding enrichment, but they should not be scored like a display-tank companion.
Water
68
Behavior
25
Predation
12
Setup
92
⚠ Relationship type: live food / prey, not tankmate.
⚠ Temperature and long-term habitat must still be understood.
What Is The Fish Compatibility Checker?

A smarter way to plan fish tankmates before problems happen.

The SpawnOS Fish Compatibility Checker is a free aquarium planning tool designed to help fish keepers understand whether two aquatic animals can safely share the same aquarium. Most compatibility charts only give a simple yes or no. That is not enough. Real aquarium compatibility depends on water temperature, pH, hardness, salinity, temperament, adult size, fin-nipping risk, predation, flow preference, tank size, hiding space, and whether one organism is meant to be a companion or food.

A betta and daphnia should not be scored like two community fish. A betta may eat daphnia as live food. That relationship can be useful, but it is not a stable tankmate pairing. A cherry shrimp and betta may share similar water, but the shrimp can still be hunted. A hillstream loach and neon tetra may overlap in some parameters, but they often prefer different habitat styles: one likes cooler, oxygen-rich flow while the other is usually kept in calmer planted community aquariums.

SpawnOS was built to make these distinctions clearer. Instead of only asking “Can they survive in the same water?” the calculator asks a better question: can they realistically thrive together in the same aquarium setup?

Why Compatibility Matters

A peaceful aquarium starts before the fish are added.

Many aquarium problems begin at the stocking stage. Fish are mixed because they look good together, fit the same theme, or appear on the same store shelf. But visual appeal does not guarantee compatibility. A community tank needs animals that can share water, space, food, flow, territory, and behavior patterns without constant stress.

01

Stress can be invisible

Fish may not show obvious fighting, but chronic stress from wrong tankmates can lead to hiding, poor appetite, faded color, fin damage, disease, and shortened lifespan.

02

Parameters are only the start

Two species can overlap in pH and temperature while still being a poor match because of aggression, speed, flow preference, adult size, or feeding behavior.

03

Predator/prey is not compatibility

Daphnia, scuds, baby shrimp, fry, worms, and microfauna may be beneficial live foods, but they are not always true long-term companions.

How It Works

The calculator breaks compatibility into relationship type, risk, and setup.

The SpawnOS compatibility engine compares two entries from the species and aquatic life database, then returns a score, verdict, relationship type, warnings, notes, parameter overlap, and recommended setup guidance.

First, it identifies the relationship.

This is the most important upgrade. Not every pairing is a normal tankmate pairing. Some combinations are display fish. Some are cleanup crew. Some are live food. Some are predator and prey. Some should be species-only. By classifying the relationship first, the tool can explain the result with more context.

Tankmates Conditional Community Live Food Predator / Prey Species-Only Conflict

Relationship Intelligence

  • Betta fish and daphnia are treated as a live food relationship, not a long-term tankmate pairing.
  • Axolotls are flagged as species-only animals because fish can nip their gills, stress them, or be eaten.
  • Shrimp and small fry are flagged for predation risk when paired with hunting or opportunistic fish.
  • Freshwater and saltwater animals are blocked as a fundamental salinity mismatch.
  • Cold-water and warm-water animals are flagged when their long-term comfort zones conflict.

Then, it separates the score into useful categories.

A single number can hide the real issue. A pairing might have a strong water match but a weak behavior match. Another might have safe behavior but poor temperature overlap. SpawnOS breaks compatibility into subscores so aquarists can see exactly what is helping or hurting the pairing.

Compatibility Subscores

  • Water Match: pH, GH, and chemistry overlap.
  • Temperature Match: whether both animals can thrive in the same heat range.
  • Behavior Match: aggression, territory, fin-nipping, and social risk.
  • Predation Safety: whether one organism may hunt, eat, or suppress the other.
  • Habitat Match: flow, oxygen, planted layout, and environmental style.
  • Setup Ease: how difficult the aquarium must be to make the pairing work.
What The Calculator Checks

Built for real aquarium logic, not just basic charts.

🌡

Temperature

Warm-water fish, cool-water fish, axolotls, goldfish, hillstream loaches, and tropical species are not always interchangeable, even when they can technically survive.

pH

Water Chemistry

The calculator compares pH and hardness ranges to identify whether both animals can live in the same water without long-term stress.

⚔

Behavior

Territorial fish, fin nippers, slow-moving fish, sensitive fish, schooling fish, and species-only animals are handled differently.

◎

Predation

The tool identifies when one animal is likely to eat or hunt the other, including live foods, baby shrimp, fry, worms, daphnia, and microfauna.

↯

Flow & Habitat

Some animals prefer calm planted aquariums. Others need high oxygen and strong flow. SpawnOS highlights these hidden mismatches.

▣

Tank Setup

The calculator suggests minimum tank size, planting level, hiding needs, flow style, zone planning, and temperature strategy.

Example Compatibility Results

Why context beats a simple yes or no.

Betta Fish × Cherry Shrimp

This is not automatically safe and not automatically impossible. The calculator treats it as a conditional community pairing because many bettas hunt shrimp, especially baby shrimp. A heavily planted tank with moss, leaf litter, and hiding space can improve survival, but individual betta temperament matters.

Likely Result

  • Water may overlap.
  • Predation risk remains significant.
  • Dense planting improves odds.
  • Baby shrimp are most vulnerable.
  • Best treated as conditional, not guaranteed.

Betta Fish × Daphnia

Daphnia are live food, not display tankmates. A betta may eat them quickly, which can be useful for enrichment and feeding variety. SpawnOS explains the relationship as predator/prey or live food instead of calling the pairing simply “bad.”

Likely Result

  • Daphnia are useful as live food.
  • They are not long-term tankmates.
  • The result should explain feeding context.
  • Parameter differences still matter for culturing.
  • Best used intentionally, not as a community animal.

Neon Tetra × Hillstream Loach

This is a more nuanced pairing. They may overlap in some parameters, but hillstream loaches prefer strong flow, high oxygen, and cooler water. Neon tetras are usually kept in calmer planted community aquariums. SpawnOS flags it as a habitat-based caution rather than a random incompatibility.

Likely Result

  • Temperature overlap may be narrow.
  • Flow preference differs.
  • High oxygen matters for hillstream loaches.
  • Setup design determines success.
  • Not impossible, but not effortless.

Guppy × Zebra Danio

This can be a workable community pairing in the right tank. Both are active fish, but danios often prefer slightly cooler water and more swimming space. The calculator should explain the shared overlap and recommend a tank that respects both species instead of blindly scoring the pair as perfect.

Likely Result

  • Usually possible in a community tank.
  • Best in a 20+ gallon aquarium.
  • Keep danios in groups.
  • Avoid overly warm guppy-only temperatures.
  • Open swimming space matters.
Part Of The Blackwater Aquatics Ecosystem

Compatibility planning connects directly to healthier fish.

Blackwater Aquatics Canada focuses on live foods, aquarium education, betta breeding, shrimp keeping, microfauna, and practical fish care. SpawnOS adds the software layer: calculators, species data, breeding tools, compatibility logic, and aquarium intelligence.

Use The Compatibility CheckerCompare fish, shrimp, snails, axolotls, live foods, and microfauna before mixing them. Live Scuds CanadaHigh-protein live food and microfauna for fish conditioning, enrichment, and natural feeding behavior. Live Daphnia CanadaA useful live food for fry, small fish, bettas, guppies, and natural feeding enrichment. Raise Betta FryLearn how feeding, water quality, and live foods affect fry survival and growth. Microworm Culture GuideSupport early fry growth with one of the most practical starter live foods for breeders. Species DatabaseResearch aquarium species, water parameters, behavior, feeding, breeding, and compatibility.
Why Use A Compatibility Calculator?

Because aquarium compatibility is not one-dimensional.

A basic compatibility chart might say two species are compatible because they are both freshwater. That is not enough. Freshwater includes cool mountain streams, tropical blackwater creeks, hard alkaline livebearer habitats, fast-flowing oxygen-rich rivers, still planted ponds, brackish estuaries, and specialized species-only environments.

The best aquarium planning looks at the whole picture. A tankmate should not merely survive. It should have room to behave naturally, feed without being bullied, avoid constant stress, and live within its preferred water conditions. The SpawnOS Fish Compatibility Checker is designed to support that kind of decision making.

This matters whether you are planning a betta community tank, a shrimp tank, a guppy tank, a planted nano aquarium, a cichlid setup, a fry grow-out system, or a live-food-based breeding project. Better planning means fewer impulse mistakes, fewer stressed fish, fewer preventable losses, and a more stable aquarium long term.

FAQ

Fish Compatibility Checker FAQ

What is the SpawnOS Fish Compatibility Checker?

The SpawnOS Fish Compatibility Checker is a free aquarium tool that compares two aquatic animals and estimates whether they can safely share a tank. It checks water parameters, temperature, behavior, predation risk, habitat needs, and setup difficulty.

Is this just a fish compatibility chart?

No. A chart usually gives a basic yes or no. The SpawnOS calculator gives a relationship type, score, subscores, risk flags, warnings, notes, and setup recommendations.

Can I use it for shrimp and snails?

Yes. The calculator is designed for fish, shrimp, snails, axolotls, microfauna, and live foods. It can identify when a pairing is a true tankmate situation versus a predation or feeding relationship.

Why would daphnia be incompatible with bettas if bettas eat daphnia?

Daphnia can be useful live food for bettas, but that does not make them permanent tankmates. The calculator separates feeding relationships from community compatibility.

Can bettas live with shrimp?

Sometimes, but it depends heavily on the betta, tank size, planting, hiding places, and shrimp size. Many bettas hunt shrimp, especially baby shrimp, so the calculator treats this as conditional.

Does the calculator replace aquarium research?

No. It is a planning tool. Always research both species, observe behavior, test water, and adjust your aquarium setup based on real conditions.

Who built the calculator?

The calculator is part of SpawnOS, an aquarium intelligence platform by Blackwater Aquatics Canada.

Plan Before You Stock

Build a smarter aquarium before the fish ever touch the water.

Use the SpawnOS Fish Compatibility Checker to compare tankmates, identify risks, understand predator/prey relationships, and plan a setup that gives your fish the best chance to thrive.

Use The Free Compatibility Checker Shop Live Scuds

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