Red Sea KH Coralline GRO 5000 ml

Coralline algae will grow naturally, without any special supplements in all reef systems optimized for hard corals. KH Coralline Gro is a complex of carbonate buffers, potassium and trace elements such as iron, formulated in the ratio taken up regularly by the coralline algae. To promote coralline algae in fish only or soft coral aquariums the alkalinity needs to be maintained at approximately 3 meq/L (8.4 °dKH) and specific minor and trace elements need to be readily available.

Dosage & Directions

Concentration. 1 ml raises the alkalinity of 100 litres / 25 gallons by 0.1 dKH (0.03 meq/l). Red Sea’s dosing chart on the pack is written for 100 litres / 25 gallons, so work out your real water volume first: display plus sump, less the volume taken up by rock and sand.

Target. To promote coralline algae in a fish-only or soft-coral system, alkalinity needs to sit at about 3 meq/L (8.4 dKH).

Before every test. Check salinity and correct it if needed, then wait 10 minutes for the water to settle before testing. Test with a high-resolution kit: Red Sea’s KH/Alkalinity Pro titration test reads to 0.05 meq/L (0.14 dKH).

Where to add it. Into the sump. If you have no sump, add it slowly into an area of high flow so it never touches corals directly.

Daily dosing, which is what boosts coralline. Get alkalinity to the optimal level, then run the tank for 4 days at stable salinity, topping up evaporation daily, without adding any supplement. Test at the end of the 4 days and work out the dose needed to bring alkalinity back to optimal. Add that whole “4-day dosage”, then divide it by four and use the result as the daily dose for the next week. Test again after a week and adjust the daily dose up or down. If the measured level is above optimal, wait for the excess to be used up before restarting.

The one hard limit. Never raise alkalinity by more than 0.5 meq/l (1.4 dKH) in a day. Bigger corrections get spread over several days. If you miss a day or more, add the total you missed, but not if it would breach that daily maximum.

Compatibility

Marine and reef aquariums.

Use it instead of Foundation B, not alongside it. Red Sea’s instruction is that KH Coralline Gro replaces the regular buffer supplement (Foundation B / KH-Alkalinity) during the cycling of every new marine aquarium, and on an ongoing basis in fish-only and soft-coral systems.

Do not use it together with Foundation ABC+. That is Red Sea’s own note, and it is there because both products carry overlapping elements.

KH Coralline Gro already contains potassium and iron. If you also dose a potassium or iron supplement, Red Sea’s Trace-Colors Potassium+ and Iron+ for instance, dose them only to a measured uptake of each element, never on a fixed schedule.

Dose it against a measured drop in alkalinity read with a high-resolution KH test, not on a timetable.

Pack Size

This is the 5 litre container: the largest format we carry of KH Coralline Gro, and the one that makes sense on a system dosing daily against a measured alkalinity drop.

One thing to know about the size. Red Sea’s own published container table for this product lists two formats, 100 ml and 500 ml. They do not publish a 5 litre pack anywhere, so the figure on this listing is our measurement of the container we hold rather than a Red Sea catalogue size. Everything else on this page (the concentration, the dosing method, the compatibility notes) is Red Sea’s own and applies whatever the container size.

What 5 litres is worth in dosing terms. At Red Sea’s stated concentration, 1 ml raises 100 litres by 0.1 dKH. Put practically: a 300-litre system replacing 0.5 dKH a day needs about 15 ml daily, and this container holds roughly eleven months of that, our arithmetic from Red Sea’s figure, not a Red Sea claim. Work it out against your own real water volume, display plus sump, less rock and sand.

Freshness & Storage

Every batch we dispatch carries a minimum of 6 months’ remaining shelf life. Store this product in a cool, dry place away from direct sunlight, with the cap or inner foil closed tightly after each use.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 48 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.