How much light and flow does Maxima clam need?

Clam, very high light at roughly 300–400 µmol·m⁻²·s⁻¹ PAR, with medium flow. Light and flow must match: high light with weak flow burns tips, strong flow with weak light thins the tissue.

Will Maxima clam attack neighbouring corals?

It shows no real aggression and can sit close to neighbours, though it still must not be shaded from above.

Does Maxima clam need feeding?

Optional. It survives without feeding, but regular small doses improve growth and colour.

What water parameters does Maxima clam need?

24–27 °C, specific gravity 1.024–1.026, 7–9 dKH, 400–450 mg/L calcium, 1250–1350 mg/L magnesium. That is only 2 dKH wide, so stability matters more than hitting a particular number.

Is Maxima clam a good beginner coral?

Difficulty: moderate. Growth: medium. Place it in the foreground / specimen. Spacing: settle it on rock or in a shallow sand hollow, and keep it away from a crocea — both compete for position with byssal threads.

G-03 / 26Marine

Maxima clam长砗磲

Tridacna maxima · Tridacnidae

Maxima clam: the most ornately patterned tridacnid, needing slightly less light than a crocea and living off its zooxanthellae just the same.

Illustration to come

G-03 / 26 · Maxima clam Tridacna maxima

SpecificationsCoral atlas

Name: 长砗磲
Scientific name: Tridacna maxima
Family: Tridacnidae
Origin: Shallow reefs of the Indo-Pacific, from the Red Sea to French Polynesia
Type: Clam
Light: Very high light
PAR: 300–400
Flow: Medium flow
Aggression: No aggression
Feeding: Optional feeding
Alkalinity: 7–9 dKH
Calcium: 400–450 mg/L
Magnesium: 1250–1350 mg/L
Salinity: 1.024–1.026 SG
Growth: Medium
Placement: Foreground / Specimen
Level: Moderate

Water requirementsMarine

Temp.24–27 °C

pH8.1–8.4

Salinity1.024–1.026 SG

Alkalinity7–9 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Spacing: settle it on rock or in a shallow sand hollow, and keep it away from a crocea — both compete for position with byssal threads.
2Flow: medium to strong, enough to keep water moving over the mantle and carry sediment away.
3Feeding: optional — juveniles under 3 cm need phytoplankton, while larger clams do fine on light alone.
4Water tolerance: stability matters more than the exact number; the first sign of a calcium or alkalinity swing is a white, stalled shell edge.
5Growth form: the shell thickens with age and adults reach 20-30 cm; how fast it grows is a direct readout of whether the light is strong enough.

Frequently asked questions

How much light and flow does Maxima clam need?: Clam, very high light at roughly 300–400 µmol·m⁻²·s⁻¹ PAR, with medium flow. Light and flow must match: high light with weak flow burns tips, strong flow with weak light thins the tissue.
Will Maxima clam attack neighbouring corals?: It shows no real aggression and can sit close to neighbours, though it still must not be shaded from above.
Does Maxima clam need feeding?: Optional. It survives without feeding, but regular small doses improve growth and colour.
What water parameters does Maxima clam need?: 24–27 °C, specific gravity 1.024–1.026, 7–9 dKH, 400–450 mg/L calcium, 1250–1350 mg/L magnesium. That is only 2 dKH wide, so stability matters more than hitting a particular number.
Is Maxima clam a good beginner coral?: Difficulty: moderate. Growth: medium. Place it in the foreground / specimen. Spacing: settle it on rock or in a shallow sand hollow, and keep it away from a crocea — both compete for position with byssal threads.