Is Tonina a Good Plant for Arapaima?

Tonina fits inside the water range normally used for Arapaima. The shared window is about 24 to 30 °C, pH 6 to 6.8, and 2 to 5 dGH, which gives you enough room to aim for stable middle-ground conditions.

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

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

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

Tonina has moderate cover density, low uproot resistance, and delicate leaves. It can also help with breaking up sight lines 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.

Tonina 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.

Tonina reaches about 30 cm tall by 5 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 and shrimp refuge. Place it where Arapaima can actually use that structure instead of hiding the plant where it cannot do much.

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.

Tonina 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.