Red Sea KH Coralline Gro 500ml — KH Buffer and Trace Elements for Coralline Algae

The Red Sea KH Coralline Gro is a marine buffer supplement built for one job: giving coralline algae the alkalinity and trace elements they draw from the water, so the pink and purple crust of a healthy reef actually spreads across your rock.

In this official Red Sea video, the Reef Care Program that KH Coralline Gro belongs to is explained from the ground up — a good starting point before dosing anything.

A KH buffer formulated for coralline algae

The formula blends carbonate buffers, potassium and trace elements such as iron, in the ratio coralline algae regularly take up. Red Sea is upfront about it: in a reef tank already optimized for hard corals, coralline grows naturally without any special supplement. KH Coralline Gro targets the other cases — cycling a brand-new saltwater aquarium, and fish-only or soft coral systems, where alkalinity should be maintained at approximately 3 meq/L (8.4 °dKH) with minor and trace elements readily available.

When and how to dose

During the cycling of any new marine aquarium, KH Coralline Gro is used instead of the Reef Foundation B (buffer) supplement, then on an ongoing basis in fish-only or soft coral tanks. Dose according to a measured drop in alkalinity with a KH/Alkalinity test kit: 1 ml raises the alkalinity of 100 liters (25 gal) by 0.1 dKH (0.03 meq/l). Size: 500 ml (16.9 fl. oz.) — the same formula also comes as a 100 ml bottle inside the Reef Mature Pro kit.

Our advice

Coralline Gro helps — it always helps — but it will not do the job for you. What really matters is that your parameters stay stable and everything is right in the tank. That is what encourages coralline to spread. — Stéphane, Aquarium ReefSolution

Why buy at ReefSolution

Authorized Red Sea dealer in Laval, QC, with fast shipping across Canada. To build the full program: the Reef Mature Pro Starter Kit includes a 100 ml KH Coralline Gro for maturing new tanks, the Marine Care Multi Test Kit tracks all your parameters during cycling, and Foundation B KH/Alkalinity takes over once stony corals move in.

Frequently asked questions

What is the difference between KH Coralline Gro and Foundation B?

Both raise alkalinity, but KH Coralline Gro adds potassium and trace elements such as iron, in the ratio taken up by coralline algae. Red Sea recommends using it instead of Foundation B while cycling a new tank, then on an ongoing basis only in fish-only or soft coral systems.

How do I dose KH Coralline Gro in my reef tank?

According to the measured drop in alkalinity with your KH test kit: 1 ml raises the alkalinity of 100 liters (25 gal) by 0.1 dKH (0.03 meq/l). Red Sea recommends keeping alkalinity at approximately 3 meq/L (8.4 °dKH) in fish-only or soft coral tanks.

Do I need it in an SPS tank?

According to Red Sea, no: in a system optimized for hard corals, coralline algae develop naturally without a dedicated supplement. This product is aimed at new tank start-ups and systems without stony corals.