What Fish Can Live Together? Compatibility Chart

Table of Contents

• Why Fish Compatibility Matters
• Key Factors That Determine Compatibility
• Fish Compatibility Chart
• Common Bad Combinations to Avoid
• Stocking Suggestions by Tank Size
• Singapore-Specific Considerations
• Frequently Asked Questions

Why Fish Compatibility Matters

One of the most common mistakes in fishkeeping is mixing species that simply cannot coexist peacefully. The result is stress, aggression, fin-nipping, or worse — dead fish. Whether you are setting up your first community tank in your HDB flat or upgrading to a larger planted aquascape, understanding which fish can live together is absolutely essential.

At Gensou, we have spent over 20 years helping Singapore hobbyists build thriving community aquariums. This guide provides a comprehensive compatibility chart and practical stocking suggestions tailored to the tanks and species most popular here.

Key Factors That Determine Compatibility

Before consulting any chart, it helps to understand the principles behind fish compatibility. These factors determine whether two species can share a tank harmoniously.

Size Difference

A general rule: if one fish can fit another in its mouth, it probably will. Avoid pairing large predatory species with tiny nano fish. A full-grown angelfish, for example, can easily swallow a neon tetra.

Temperament

Fish temperaments range from peaceful (most tetras, rasboras) to semi-aggressive (barbs, some gouramis) to aggressive (many cichlids). Mixing extremes rarely ends well.

Water Parameters

Singapore’s tap water (after dechlorination with a conditioner that handles PUB’s chloramine) typically sits at pH 7.0–7.5 and is moderately soft. Most common tropical freshwater species thrive in these conditions, which simplifies compatibility here compared to other countries.

Territory and Swimming Level

Fish that occupy different zones — surface, mid-water, and bottom — tend to coexist better. Territorial bottom-dwellers like plecos may clash with other bottom-dwellers but ignore mid-water tetras entirely.

Temperature

Singapore’s ambient temperature of 28–32 °C suits most tropical species without a heater. However, some cool-water fish (white cloud minnows, hillstream loaches) may struggle during our hottest months unless you have a chiller or fan.

Fish Compatibility Chart

Use this chart as a quick reference. C = Compatible, ! = Caution (may work with conditions), X = Incompatible.

Notes on the Chart

• Tetras + Barbs (!): Tiger barbs are notorious fin-nippers. Cherry barbs are generally peaceful — species matters enormously.
• Cichlids (!): This category spans peaceful apistos to aggressive Oscars. Dwarf cichlids (rams, apistos) can work in community tanks; large cichlids typically cannot.
• Bettas + Shrimp (!): Some bettas ignore shrimp entirely; others hunt them relentlessly. It depends on individual temperament and dense plant cover.
• Gouramis + Gouramis (!): Male gouramis (especially dwarf gouramis) can be territorial with each other. One male per tank is safest unless the tank is large and well-planted.

Common Bad Combinations to Avoid

These pairings are frequently attempted by beginners and almost always end poorly.

Stocking Suggestions by Tank Size

These are practical community combinations that work well in Singapore’s warm water conditions (28–30 °C without a chiller). All assume the tank is properly cycled and filtered.

60-Litre Tank (Approximately 2 Feet)

• Option A — Nano Community: 8 ember tetras, 6 chilli rasboras, 6 pygmy corydoras, a few cherry shrimp
• Option B — Betta Community: 1 male betta, 6 harlequin rasboras, 4 pygmy corydoras, 3 nerite snails
• Option C — Livebearer Tank: 6 endler’s livebearers (1 male : 2 females), 6 celestial pearl danios, 5 amano shrimp

120-Litre Tank (Approximately 3 Feet)

• Option A — Classic Community: 12 cardinal tetras, 8 harlequin rasboras, 8 corydoras sterbai, 1 bristlenose pleco, 10 amano shrimp
• Option B — Southeast Asian Biotope: 10 harlequin rasboras, 6 kuhli loaches, 1 pair of honey gouramis, 1 bristlenose pleco
• Option C — Livebearer Community: 8 guppies (2M:6F), 6 platies, 8 corydoras panda, 5 amano shrimp

200-Litre Tank (Approximately 4 Feet)

• Option A — Planted Showpiece: 20 cardinal tetras, 10 rummy-nose tetras, 10 corydoras sterbai, 1 pair of German blue rams, 1 bristlenose pleco, 15 amano shrimp
• Option B — Diverse Community: 12 harlequin rasboras, 8 cherry barbs, 6 kuhli loaches, 1 pair of pearl gouramis, 1 bristlenose pleco
• Option C — Angelfish Tank: 4 angelfish, 12 rummy-nose tetras (too fast to eat), 8 corydoras, 1 bristlenose pleco

Singapore-Specific Considerations

A few points that are particularly relevant for hobbyists here:

• No heater needed: Our ambient temperature of 28–32 °C is already in the tropical range. This is actually a slight advantage for compatibility — most species sold at local fish shops are suited to this range.
• Chloramine in tap water: PUB uses chloramine, not just chlorine. Always use a water conditioner that neutralises chloramine (such as Seachem Prime) when doing water changes. This applies regardless of which species you keep.
• Cool-water species caution: White cloud minnows and some hillstream loaches prefer temperatures below 26 °C. In a non-air-conditioned HDB flat, summer temperatures can push 32 °C, which stresses these fish. A clip-on fan helps but may not be sufficient.
• Space constraints: Many HDB and condo dwellers work with 2- to 3-foot tanks. The stocking suggestions above for 60L and 120L tanks are designed with these typical setups in mind.

Frequently Asked Questions

Can I keep different species of tetras together?

Yes, most tetra species are compatible with each other. Cardinal tetras, neon tetras, ember tetras, and rummy-nose tetras all coexist peacefully. Keep each species in groups of at least 6 so they school properly and feel secure.

How many fish can I put in my tank?

The old “one inch of fish per gallon” rule is a rough starting point but has significant limitations. A better approach is to consider the adult size of each species, their bio-load (how much waste they produce), your filtration capacity, and how often you do water changes. When in doubt, understock. You can always add more later.

Can shrimp live with fish safely?

Amano shrimp are large enough to coexist with most peaceful community fish. Cherry shrimp (neocaridina) are smaller and more vulnerable — they do best with tiny, peaceful species like chilli rasboras and ember tetras, or in a dedicated shrimp-only tank. Dense plant cover such as Java moss and Bucephalandra significantly improves shrimp survival in community setups.

What if my fish are fighting even though the chart says they are compatible?

Individual temperament varies, and tank size matters enormously. If aggression occurs, check that schooling fish are in adequate numbers (small groups cause stress and nipping), ensure there are enough hiding spots and visual barriers (plants, rocks, driftwood), and confirm the tank is not overstocked. Sometimes, a specific individual is simply a bully and needs to be rehomed.

Build Your Perfect Community Tank

Choosing compatible fish is the foundation of a peaceful, thriving aquarium. If you are unsure about a particular combination or want a professionally designed community tank, our team at Gensou can help. With over 20 years of aquascaping experience in Singapore, we design custom aquariums and provide ongoing maintenance services to keep your community healthy. Visit us at 5 Everton Park or get in touch to discuss your ideal setup.

Related Reading

• Aquarium Fish Compatibility Chart: Printable Quick Reference
• Fish Compatibility Chart: What Can Live Together
• How to Use Aquarium Fish Compatibility Checkers Effectively
• 10 Fish Compatibility Mistakes Beginners Make
• Aquarium Fish Lifespan Chart: How Long Do They Really Live?