Red Sea Reef Care KH/Alkalinity Foundation B
Cost per litre
Under 1c
Water type
Marine/Reef
Red Sea Reef Care KH/Alkalinity Foundation B
Holds your reef's most volatile parameter steady. Red Sea Reef Foundation B is the ready-to-use liquid alkalinity (KH) component of Red Sea's three-part Reef Foundation program, replenishing the carbonate that corals consume fastest as they build skeleton. It ships as a blend of carbonates balanced to the ratio found in natural seawater, and needs no mixing — measure and dose straight from the bottle.
Key features
- Precise, predictable dosing — 1 mL per 100 L (25 US gal) raises alkalinity by 0.1 dKH (0.036 meq/L), so small daily corrections are easy to calculate.
- Balanced to natural seawater ratios — a blend of carbonates formulated to avoid the ionic imbalances that plain baking soda or washing soda dosing can cause over time.
- Pairs with Foundation A and C — designed to be dosed alongside Calcium (A) and Magnesium (C) so alkalinity doesn't rise in isolation and strip the other two.
- Ready to use — no mixing, no RO/DI water needed, works with any dosing pump or manual dosing routine.
- Ultra-low cost per correction — see Cost per litre below; the 5 L pack works out cheapest per dKH raised.
Specifications
| Size | SKU | Dose for +0.1 dKH | Form |
|---|---|---|---|
| 500 mL | RED281 | 1 mL per 100 L | Ready-to-use liquid |
| 1 L | RED281b | 1 mL per 100 L | Ready-to-use liquid |
| 5 L | RED281a | 1 mL per 100 L | Ready-to-use liquid |
Cost per litre
Buying Foundation B by the litre of alkalinity correction, not the bottle price, is the fair way to compare pack sizes. A full 500 mL bottle carries enough to raise 5,000 L of tank water by 1 dKH; the 5 L pack raises 50,000 L by the same 1 dKH. At current prices, that works out to roughly $5.80 per 1,000 L corrected on the 500 mL bottle, falling to about $3.42 per 1,000 L on the 5 L pack — both round to under 1c per litre on the product tile, but the 5 L is genuinely the cheaper way to buy if you dose a display tank regularly.
| Size | Price | Litres raised 1 dKH per pack | Cost per 1,000 L corrected |
|---|---|---|---|
| 500 mL | $29.00 | 5,000 L | $5.80 |
| 1 L | $45.00 | 10,000 L | $4.50 |
| 5 L | $171.00 | 50,000 L | $3.42 |
Dosage and directions
Dose to measured demand, not to a schedule. Test alkalinity before dosing, then add 1 mL per 100 L of tank water for every 0.1 dKH you need to raise it, split across small daily doses rather than one large correction. KH is the parameter worth testing most often on a reef tank — aim for stability at a chosen number rather than chasing a "perfect" figure.
Can I dose Foundation B by hand?
Yes. It's sold as a manual-dosing liquid and also works through any peristaltic or gravity dosing pump set up for the Reef Foundation program.
How often should I dose?
Daily, in small amounts, based on your last test result. Large infrequent corrections cause the swings that trigger coral stress, not the stability the product is designed to hold.
Suitable for, and not suitable for
Suitable for marine and reef aquariums running a KH/alkalinity dosing regime, alongside Foundation A (Calcium) and Foundation C (Magnesium). Not a substitute for regular alkalinity testing — dosing without testing risks overshooting a tank with low demand. Not intended for freshwater aquariums.
Safety
Keep out of reach of children and pets. Avoid prolonged skin and eye contact and rinse with water if it occurs. Store away from direct sunlight. Safe for fish, coral and invertebrates when dosed at the recommended rate — as with any concentrate, don't pour it directly onto livestock or coral tissue.
Goes well with
- Red Sea Reef Care Calcium+ Foundation A — the calcium half of the same three-part program; alkalinity and calcium need to move together.
- Red Sea Reef Care Magnesium Foundation C — magnesium is what lets calcium and alkalinity hold their levels once you've dialled them in.
- Red Sea Reef Foundation Pro Multi Testing Kit — for measuring KH before you dose, not after.
- Red Sea Reef Care KH/Alkalinity Foundation B (Powder) — same element in a concentrated dry format, cheaper per litre corrected on larger systems.
Warranty and delivery
Covered by the manufacturer's standard consumer guarantees in addition to your rights under Australian Consumer Law. Standard parcel delivery Australia-wide.
Common questions
What's the difference between Foundation B liquid and Foundation B powder?
Both replenish the same carbonate alkalinity. The liquid is ready to dose straight from the bottle; the powder is mixed into a stock solution with RO/DI water and works out cheaper per litre of correction on larger systems.
Can I dose Foundation A, B and C at the same time?
Dose them separately, at different times or through separate dosing pump heads. Mixing concentrated calcium and alkalinity solutions together before dilution can cause them to precipitate.
Will Foundation B affect my calcium or magnesium levels?
Not directly, but raising alkalinity without keeping calcium and magnesium in step is what causes the "chasing your tail" swings reef keepers describe — dose all three against their own test results.
How long will a bottle last?
It depends entirely on your tank's alkalinity demand — a heavily stocked SPS system will use it faster than a soft coral tank. Use the cost-per-litre figures above against your own dosing log to estimate it.
