Caulerpa peltata
| Care Level | Easy |
| Lighting | Moderate to high |
| Water Flow | Moderate |
| Placement | Refugium or display |
| Primary Use | Nutrient export & herbivore food |
| Growth Rate | Fast |
Overview
Caulerpa peltata is a green Caulerpa — a form of the sea-grape Caulerpa racemosa — whose runners are studded with small, flattened, disc- or shield-shaped caps instead of round grapes, giving it a distinctive scalloped look. It is a fast-growing refugium workhorse and a favorite herbivore food.
Care & Placement
Easy. Moderate to high light and moderate flow, in a refugium or the display. It grows fast, so harvest it regularly. As with all Caulerpa, keep it well lit (24/7 in a fuge or on a reverse-light cycle) to discourage it from “going sexual.”
Uses & Nutrient Export
It rapidly takes up nitrate and phosphate, so it is excellent for nutrient export — harvest and discard growth to remove those nutrients. It is also a prime herbivore food that tangs and other grazers relish.
Propagation & Harvesting
It spreads quickly via runners; simply pull and discard (or feed) the excess to keep it in check and export nutrients. Frequent harvesting also helps prevent it from going sexual.
Cautions
Like all Caulerpa, it can “go sexual” — a sudden mass release of spores that turns the alga white, clouds the water, and dumps nutrients back into the tank. Prevent it by harvesting regularly, keeping steady light, and avoiding big disturbances. It can also be invasive, so contain it.
Frequently Asked Questions
Is Caulerpa peltata the same as sea grapes?
It is closely related — it is a form of Caulerpa racemosa (sea grapes), but with flattened disc- or shield-shaped caps instead of round beads. Care is the same as other green Caulerpa.
How do I stop Caulerpa from going sexual?
Harvest it frequently, keep the lighting steady (24/7 in a refugium or on a reverse cycle), and avoid large disturbances. Going sexual is a sudden spore release that clouds the water and returns nutrients, so keeping it actively growing and trimmed is the best prevention.
Is Caulerpa peltata good for a refugium?
Yes — it is fast-growing and a strong nitrate and phosphate exporter, and it doubles as excellent herbivore food. Just harvest it regularly and keep it lit to avoid a sexual event.