Red Sea Foundation B 5 Litres

Dosage & Directions

Which figure applies to this pack. This listing is the ready-mixed 5-litre liquid, so the liquid concentration is the one to use: 1 ml raises the alkalinity of 100 litres / 25 gallons by 0.036 meq/l (0.1 dKH). The powder figure quoted above is for Red Sea’s separate 1 kg powder pack.

Work out your volume first. Red Sea’s dosing chart is written for 100 litres / 25 gallons. Use display plus sump, less the volume of rock and sand.

Targets. Red Sea publish optimal salinity, alkalinity, calcium and magnesium levels by aquarium type in the Foundation manual. The alkalinity targets there span roughly 6.8 to 12.6 dKH depending on the type and maturity of the coral population — a fish-heavy system sits at the low end, an ultra-low-nutrient SPS system at the high end.

Before every test. Check salinity and correct it, then wait 10 minutes. A 1 ppt rise in salinity from evaporation alone shifts calcium by about 13 ppm and magnesium by about 40 ppm, so testing a drifted tank gives you a dose for a tank you do not have.

Order matters. When dosing more than one foundation element, add them in this order with 10 minutes between each: magnesium first, then alkalinity, then calcium. Add everything to the sump; without a sump, add slowly into high flow away from fish and corals.

The daily-dosing routine. Bring all the foundation elements to optimal, then run 4 days at stable salinity — topping up evaporation daily — with no supplements at all. Test, calculate the dose that returns each element to optimal, add that whole “4-day dosage”, then divide by four for the daily dose over the following week. Retest weekly and amend. Keep a log: as corals grow and stock changes, uptake changes with them.

Weekly dosing is Red Sea’s recommendation for marine-fish systems — test weekly and dose back to optimal.

The one hard limit. Never raise alkalinity by more than 0.5 meq/l (1.4 dKH) in a day (the matching limits are 20 ppm for calcium and 10 ppm for magnesium). Larger corrections get spread across days. If you miss doses, make them up — but never past the daily maximum.

Compatibility

Marine and reef aquariums. Foundation B is the buffer half of Red Sea’s Foundation program: Foundation A (Calcium+, which also carries strontium and barium), Foundation B (KH/Alkalinity, bicarbonates) and Foundation C (Magnesium).

Testing. Red Sea’s KH/Alkalinity Pro titration kit reads to 0.05 meq/L (0.14 dKH). Avoid any test kit that measures carbonates rather than total alkalinity — alkalinity is the sum of every buffering substance in the water, bicarbonate, carbonate, hydroxide and borate, and a carbonate-only reading is not the same number.

With Foundation ABC+. If you dose the ABC+ powder daily, Red Sea still expect you to test all three foundation elements weekly and make the corrections with the individual Calcium+, KH/Alkalinity and Magnesium supplements — which is exactly what this product is for.

When not to use it. During the cycling of a new marine aquarium, and on an ongoing basis in fish-only or soft-coral systems, Red Sea direct you to KH Coralline Gro instead of Foundation B.

If you make your own stock solution from the 1 kg powder pack, Red Sea dissolve it at 100 g per litre of RO water — 1 kg makes 10 litres — and that stock is weaker than this ready-made liquid, at 0.012 meq/l (0.034 dKH) per ml per 100 litres. Do not carry a dose across from one to the other.

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 72 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.