Seachem Reef Carbonate
Cost per litre
Under 1c
Water type
Marine + Reef
Seachem Reef Carbonate
Liquid alkalinity, ready for a dosing pump. Seachem Reef Carbonate is a concentrated blend of carbonate and bicarbonate salts that restores and maintains alkalinity in the reef aquarium — in liquid form, so it mixes and doses cleanly through an automated system.
Key features
- Raises and maintains carbonate alkalinity (KH).
- Liquid concentrate — each mL supplies a minimum of 4 meq of alkalinity, so it doses and dissolves instantly, unlike a powder.
- Dosing-pump friendly — a continuous-drip formula is published for automated systems.
- Pairs with a calcium supplement such as Reef Complete for balanced reef chemistry.
- Costs under 1c per litre of tank water dosed at every pack size.
Specifications
| Pack size | Price | Standard dose | Litres this pack doses |
|---|---|---|---|
| 100 mL | $9.95 | 5 mL per 80 L, twice weekly | 1,600 L |
| 250 mL | $9.75 | 5 mL per 80 L, twice weekly | 4,000 L |
| 500 mL | $19.95 | 5 mL per 80 L, twice weekly | 8,000 L |
Target alkalinity is 3–6 meq/L (8–17 dKH); Seachem states a practical minimum of 2 meq/L.
Suitable for, and not suitable for
- Suitable for reef and marine aquariums needing steady carbonate alkalinity, especially where a dosing pump is already handling other supplements.
- Not a calcium, magnesium or strontium source on its own.
- Not for freshwater aquariums.
Dosage and directions
Beginner dose: dilute 1 capful (5 mL) in freshwater and add per 80 L of system volume, twice weekly. Check alkalinity every fortnight. Each 5 mL/80 L dose raises alkalinity by roughly 0.25 meq/L; do not exceed 20 mL per 80 L in a single day.
For a continuous dosing pump, Seachem publishes the formula m = va/4, where m is mL of Reef Carbonate, v is tank volume in litres and a is the meq/L rise wanted.
Cost per litre at every pack size works out under 1c, calculated on the standard dose. The 100 mL bottle costs more per millilitre of product than the two larger sizes — buy the 250 mL or 500 mL bottle unless you only want to trial the product:
| Pack size | Cost per litre dosed |
|---|---|
| 100 mL | Under 1c per litre |
| 250 mL | Under 1c per litre |
| 500 mL | Under 1c per litre |
Safety
- Do not mix directly with a calcium, magnesium or strontium supplement — dose on alternate days or space doses at least 30 minutes apart.
- Do not exceed 20 mL per 80 L per day. Excess alkalinity can push calcium, magnesium and strontium out of solution.
- A Safety Data Sheet is available from Seachem for handling and storage guidance.
Care and storage
Keep the cap sealed between doses and store out of direct sunlight at room temperature.
Goes well with
- Seachem Reef Complete — the calcium, magnesium and strontium side of reef chemistry.
- Seachem Reef Builder — a powder alternative for dosing by hand rather than by pump.
Warranty and delivery
Covered by the manufacturer's standard warranty against defects, in addition to your rights under Australian Consumer Law. Standard freight.
Common questions
Is Reef Carbonate better than Reef Builder?
Neither is better outright — Reef Carbonate is a liquid, which suits dosing pumps and automated systems. Reef Builder is a powder, which is generally cheaper to buy in bulk if you're dosing by hand.
Which pack size should I buy?
The 100 mL bottle is priced for trialling the product and costs more per millilitre than the larger sizes. If you already know you'll be dosing regularly, the 250 mL or 500 mL bottle works out cheaper.
Can I dose it every day?
You can, up to the daily maximum of 20 mL per 80 L, but test alkalinity regularly rather than dosing to a fixed schedule.
Will this affect my calcium level?
Not directly, but alkalinity and calcium interact — pushing alkalinity too high relative to calcium can cause calcium to drop out of solution, so dose both and test both.
