Red Grape Algae

Botryocladia botryoides

Also known as Red Grape, Red grape kelp, Red Grape Caulerpa

SaltwaterMacroalgaeCuttings

Red Grape Algae (Botryocladia botryoides) — Golfopolikayak · CC BY 4.0

Care at a glance

Light: Medium light
CO2: No CO₂ needed
Temperature: 73–81°F; 23–27°C
Max height: 4.7 in; 12 cm

Growth rate: Medium
Placement: Midground
Type: Macroalgae
pH: 8.0–8.4
Spread: 5.9 in (15 cm)
Nutrient uptake: Water column
Growth region: Submersed
Difficulty: Easy
Family: Rhodymeniaceae
Origin: Warm temperate and tropical seas of the Atlantic and Mediterranean

Overview

Red Grape Algae is a hardy, decorative red macroalga that stays compact enough for nano and reef tanks without overrunning them. It is an easy plant to keep.

Did you know

Each little grape on Red Grape Algae is a hollow sac filled with fluid. A healthy cluster looks and feels like a tiny bunch of translucent red bubbles rather than a solid frond.

Caring for Red Grape Algae

Anchor Red Grape Algae to rock or shell in the midground, where its bunched vesicles show. A dab of glue or a loop of line holds it in place.

It prefers medium light and moderate flow. Too much light pales the grapes, so easing off the intensity keeps them a rich red. It needs no added CO2 and feeds from the water, drawing nitrate and phosphate as it grows. That makes it a nutrient sponge as well as a display accent. Keep it at 73 to 81°F (23 to 27°C) with a pH of 8 to 8.4.

It grows steadily at a moderate pace and spreads by fragmentation. Cut off a branch and attach it elsewhere to start a new cluster. The grapes are tasty enough that some grazing fish will pick at them.

Good to know

Red Grape Algae, Botryocladia botryoides, is a red alga in the family Rhodymeniaceae. Its small vesicles cluster on branching stalks and resemble bunches of grapes. Despite the trade name Red Grape Caulerpa, it is not a Caulerpa and carries none of that genus's go-sexual crash risk.

In the wild

Red Grape Algae lives in the warm temperate and tropical seas of the Atlantic and the Mediterranean. It grows attached to rock and shell in coastal waters.