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Is Scarlet Temple a Good Plant for Arapaima?

Reviewed by Guidarium Editorial DeskUpdated May 1, 2026
Not Recommended

Scarlet Temple is not recommended for Arapaima. The issue is practical, not cosmetic: arapaima is likely to chew or tear this plant before it settles in.

Scarlet Temple

Alternanthera reineckii

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PlacementMidground
LightHigh
DifficultyIntermediate
Size45 × 15 cm

Arapaima

Arapaima gigas

View fish profile
TemperamentAggressive
FamilyOddballs
Temp24–30°C
Water TypeFreshwater Only

Quick Decision

A plant can be technically compatible with a fish and still fail in the actual tank if the fish digs, chews, needs denser cover, or uses a different part of the layout.

Overall fit

58/100

The fish is likely to outgrow, uproot, or out-pressure the plant.

Water match

Workable overlap

Shared range: 24-28°C, pH 6-7.5, 2-12 dGH.

Plant pressure

High

Arapaima may chew, uproot, or stress this plant.

Layout value

Moderate cover

Scarlet Temple helps with breaks lines of sight, good refuge for fry, and good refuge for shrimp.

Plant and Fish Fit Notes

Use these signals to decide whether the plant is doing useful work for the fish, or whether it is only surviving beside it.

Temperature
Scarlet Temple20-28°C
Arapaima24-30°C

Overlap: 24-28°C.

pH
Scarlet Temple5.5-7.5
Arapaima6-7.5

Overlap: pH 6-7.5.

Hardness
Scarlet Temple2-12 dGH
Arapaima2-15 dGH

Overlap: 2-12 dGH.

Water and flow
Scarlet TempleFreshwater Only, Moderate (Standard)
ArapaimaFreshwater Only, Low (Still Water)

Flow expectations are close enough for one layout.

Space used
Scarlet TempleMidground and Background
ArapaimaTop (Surface) and Middle (Open Water)
Pressure signals
Scarlet TempleModerate uproot resistance, Standard leaves
ArapaimaAggressive, Piscivore (Eats small/nano fish), Jumper (Lid Required), and Hyperactive / Fast Swimmer

Plant pressure: High.

Planting value
Scarlet TempleBreaks lines of sight, Good refuge for fry, and Good refuge for shrimp, Nutrient-rich substrate preferred
ArapaimaNo special plant requirement listed

Shared Tank Conditions

Scarlet Temple fits inside the water range normally used for Arapaima. The shared window is about 24 to 28 °C, pH 6 to 7.5, and 2 to 12 dGH, which gives you enough room to aim for stable middle-ground conditions.

Their flow expectations are close enough to combine: Scarlet Temple prefers moderate flow, while Arapaima prefers gentle, low-flow water.

Both are suited to freshwater, so salinity does not add an extra planning problem.

Fish Pressure and Plant Resilience

Arapaima puts heavy pressure on plants, so this species is likely to be chewed, uprooted, or stressed in day-to-day use.

Scarlet Temple has moderate cover density, moderate uproot resistance, and standard leaves. It can also help with breaking up sight lines, fry refuge, and shrimp refuge.

Its structure adds useful refuge value beyond the normal visual role of the plant.

The limiting issue is arapaima is likely to chew or tear this plant before it settles in.

Layout Fit

Scarlet Temple is a stem plant usually used midground and background.

Arapaima is an oddball fish, so the pairing works best when the planting style supports how that fish uses space and cover.

Scarlet Temple reaches about 45 cm tall by 15 cm wide and is usually rooted in substrate with nutrient-rich substrate preferred. That makes placement and anchoring more important than simply adding a larger bunch of stems or leaves.

In this pairing, the useful plant values are line-of-sight breaks, fry refuge, and shrimp refuge. Place it where Arapaima can actually use that structure instead of hiding the plant where it cannot do much.

Practical Recommendation

For most keepers, a tougher or better-matched plant is the smarter choice. If you still try it, test with a small amount first and be ready to move the plant before it is badly damaged.

The decision should center on this signal: Arapaima is likely to chew or tear this plant before it settles in.

Best Use Case

Scarlet Temple is usually the wrong plant for Arapaima if your goal is a stable display tank. The issue is rarely one dramatic failure on day one; it is the steady mismatch between what the fish does in the scape and what the plant needs to stay attractive long term.

Frequently Asked Questions About Scarlet Temple and Arapaima

Is Scarlet Temple a good plant for Arapaima?

Scarlet Temple is not recommended for Arapaima. The issue is practical, not cosmetic: arapaima is likely to chew or tear this plant before it settles in.

Can Arapaima damage Scarlet Temple?

Arapaima is likely to chew or tear this plant before it settles in.

Do Scarlet Temple and Arapaima share the same water conditions?

Scarlet Temple and Arapaima share a workable water window around 24 to 28 °C, pH 6 to 7.5, and 2 to 12 dGH. Keep the tank near the middle of that overlap for the best long-term result.

What does Scarlet Temple add to a tank with Arapaima?

Its structure adds useful refuge value beyond the normal visual role of the plant.

What is the main risk in this plant and fish pairing?

Arapaima is likely to chew or tear this plant before it settles in.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 1, 2026
Last updated
May 1, 2026
Issues or corrections?
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