How much light does Red Ogo need?

Medium light, around 40–60 µmol·m⁻²·s⁻¹ of PAR. Watts are not comparable between fixtures; PAR is. If the manufacturer does not publish PAR, pick one band lower than the tank depth suggests.

Does Red Ogo need CO₂?

No. Marked "not needed": it grows normally in a tank with no CO₂ at all. These are usually slow growers that are also forgiving about light.

What water does Red Ogo want?

22–28 °C, pH 8–8.4, 7–12 dGH. At 5 dGH wide it is one of the more forgiving ranges.

How fast does Red Ogo grow, and where does it go?

Growth rate: fast. Placement: background / attached. Substrate: no substrate needed, reaching about 10–25 cm. Difficulty: beginner.

G-02 / 26Marine

Red Ogo江蓠

Gracilaria parvispora · Gracilariaceae

A red macroalga that grows fast, exports nutrients and doubles as natural food for algae-eating fish.

Illustration to come

G-02 / 26 · Red Ogo Gracilaria parvispora

SpecificationsPlant atlas

Name: 江蓠
Scientific name: Gracilaria parvispora
Family: Gracilariaceae
Origin: Shallow sand and rubble of the Indo-Pacific, including Hawaii, and the Caribbean
Light: Medium light
PAR: 40–60
CO₂: Not needed
Hardness: 7–12 dGH
Growth: Fast
Placement: Background / Attached
Substrate: No substrate needed
Height: 10–25 cm
Level: Beginner

Water requirementsMarine

Temp.22–28 °C

pH8–8.4

Salinity1.023–1.026 SG

Alkalinity7–12 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.

Growing notes

1The branches are soft and hold on with a small holdfast, though it also grows loose in a low-flow corner.
2Eight to twelve hours of light with medium flow suits it best, and poor flow lets debris smother it.
3Iron shortage fades the red and turns the branches white and clear, and iron plus trace elements restore it in a week or two.
4Harvest a third to a half every two or three weeks, and tie the cuttings back onto live rock to keep the culture going.
5Tangs such as the blue tang and the bristletooth tang graze it to nothing in a display, so keep a stock in the refugium.

Frequently asked questions

How much light does Red Ogo need?: Medium light, around 40–60 µmol·m⁻²·s⁻¹ of PAR. Watts are not comparable between fixtures; PAR is. If the manufacturer does not publish PAR, pick one band lower than the tank depth suggests.
Does Red Ogo need CO₂?: No. Marked "not needed": it grows normally in a tank with no CO₂ at all. These are usually slow growers that are also forgiving about light.
What water does Red Ogo want?: 22–28 °C, pH 8–8.4, 7–12 dGH. At 5 dGH wide it is one of the more forgiving ranges.
How fast does Red Ogo grow, and where does it go?: Growth rate: fast. Placement: background / attached. Substrate: no substrate needed, reaching about 10–25 cm. Difficulty: beginner.