Can Altum Angel and Thai Micro Crab Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 2, 2026
Not Recommended

Altum Angel and Thai Micro Crab are not recommended as tank mates due to incompatible hardness ranges and piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Altum Angel

Pterophyllum altum

Thai Micro Crab

Limnopilos naiyanetri

🐠Family Group
Altum Angel
Cichlids - South American
Thai Micro Crab
Invertebrates
Temperament
Altum Angel
Semi-Aggressive (5/10)
Thai Micro Crab
Peaceful (0/10)
Temperature
✓ Compatible
Altum Angel
27–32°C
Thai Micro Crab
22–28°C
pH Range
✓ Compatible
Altum Angel
4.5–6.5
Thai Micro Crab
6.5–8
Hardness (dGH)
✗ No overlap
Altum Angel
1–5
Thai Micro Crab
6–15
Water Type
✓ Compatible
Altum Angel
Freshwater Only
Thai Micro Crab
Freshwater Only
Flow Preference
✓ Compatible
Altum Angel
Low
Thai Micro Crab
Low
Min Tank Volume
Combined: 400 L
Altum Angel
400 L
Thai Micro Crab
19 L
Swimming Level
✓ Different zones
Altum Angel
Middle
Thai Micro Crab
Bottom
🏷️Behavior Tags
Altum Angel
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorTerritorial (Defends specific area)Shy / Slow Moving (Easily Stressed)
Thai Micro Crab
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)Nocturnal
Stocking calculator

Can your tank handle Altum Angel and Thai Micro Crab?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Altum Angel
Thai Micro Crab
Test both in my tank

Behaviour & Temperament

Altum Angel is a moderately assertive species (5/10), while Thai Micro Crab is peaceful (0/10). This notable difference means Altum Angel may occasionally assert dominance over Thai Micro Crab.

In terms of spatial distribution, Altum Angel prefers the Middle (Open Water) zone, whereas Thai Micro Crab occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Thai Micro Crab is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

Water Parameters

The safe temperature window for both species falls between 27°C and 28°C. Aim for the midpoint of this range (around 27.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 6.5. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Altum Angel needs 1–5 dGH while Thai Micro Crab requires 6–15 dGH.

Tank Setup

To house Altum Angel and Thai Micro Crab together, plan for an aquarium of at least 400 litres with a minimum length of 120 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Floating, Plants - Densely covered. Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Usually Fails in Practice

Altum Angel and Thai Micro Crab are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Altum Angel and Thai Micro Crab.

Diet & Feeding

Feeding time deserves special attention with this pairing. Altum Angel is a known shrimp eater and may prey on small invertebrates or nano fish like Thai Micro Crab.

Frequently Asked Questions

Can Altum Angel and Thai Micro Crab live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Altum Angel and Thai Micro Crab need?

A minimum of 400 litres (tank length at least 120 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Altum Angel and Thai Micro Crab together?

Keep the aquarium between 27°C and 28°C. A target of around 27.5°C sits comfortably within both species' preferred ranges.

Are Altum Angel or Thai Micro Crab aggressive?

Altum Angel is moderately assertive (5/10) and Thai Micro Crab is peaceful (0/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Altum Angel and Thai Micro Crab need?

Both species overlap in the 6.5–6.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Altum Angel's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Altum Angel space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Does Thai Micro Crab being nocturnal affect compatibility?

Thai Micro Crab is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Thai Micro Crab during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 2, 2026
Last updated
May 2, 2026
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