Red Sea Reef Care Skeletal Elements Foundation ABC+ 5kg
Pack size
5 kg
Water type
Saltwater + Reef
Cost per gram
2.8c
Replaces
Separate Ca, Alk, Mg
Also adds
K, B, I, Br
Form
Powder
Dose rate
1 g/100 L = +1.5 ppm Ca
Red Sea Reef Care Skeletal Elements Foundation ABC+ 5kg
The bulk tub for reefs that go through Foundation elements fast. Red Sea Skeletal Elements Foundation ABC+ blends calcium, carbonate alkalinity and magnesium – plus the potassium, boron, iodine and bromine of Coral Colours A and B – in the same proportions found in coral skeleton, so one measured scoop replaces separate dosing of each element. The 5 kg tub is the economical size for large systems, frag farms, or anyone dosing daily who doesn't want to reorder every few weeks.
Key features
- One powder, several elements – calcium, alkalinity and magnesium in coral-consumption ratio, with trace potassium, boron, iodine and bromine included.
- Built for daily dosing at scale – large or heavily-stocked reefs consuming Foundation elements daily get through a 1 kg tub quickly; 5 kg cuts down on reorder frequency.
- Lower cost per gram than the 1 kg tub – the 5 kg size is the better per-litre buy for ongoing, high-volume dosing.
- Daily or weekly dosing – add directly to flow for daily dosing, or dissolve in a bucket first for a weekly top-up.
- Under 1c per litre dosed – see Specifications for the full cost breakdown.
Specifications
| Contains | Calcium, carbonate alkalinity, magnesium, plus potassium, boron, iodine and bromine |
|---|---|
| Format | Powder |
| Pack size | 5 kg tub |
| Dose rate | 1–2 g per 100 L of aquarium water |
| Dosing frequency | Daily or weekly |
| Suitable for | Marine / reef aquariums with balanced elemental uptake, particularly larger or heavily-stocked systems |
Cost per litre dosed
| Pack | SKU | Price | Cost per litre dosed |
|---|---|---|---|
| 1 kg | RED300 | $48.50 | Under 1c per litre |
| 5 kg | RED301 | $141.95 | Under 1c per litre |
At the conservative end of the 1–2 g per 100 L dose range, the 5 kg tub covers roughly 250,000 L of cumulative dosing. Per gram it's noticeably cheaper than the 1 kg tub – $0.0284/g against $0.0485/g – so a system dosing daily works out ahead buying the larger size, provided it's used before the powder is affected by moisture over a long storage period.
Which one do I need? ABC+ powder vs liquid ABC
| Foundation ABC+ (powder, this product) | Foundation ABC 3-Pack (liquid) | |
|---|---|---|
| Dosing | One dose covers all three, in a fixed ratio | Each element dosed separately, to its own test result |
| Best for | Systems where calcium, alkalinity and magnesium deplete roughly in proportion | SPS-heavy systems where uptake is uneven across elements |
| Format | Powder, dissolved or dosed dry | Liquid, ready to dose |
Dosage and directions
Dose daily or weekly depending on your system and coral load. For daily dosing on a larger or heavily-stocked system, add the powder directly into an area of good flow – an auto-doser is worth considering at this pack size. For weekly dosing, dissolve in a bucket of aquarium water first, then add gradually. Use 1–2 g per 100 L as a starting point, and test all three foundation elements weekly; if one element drifts out of line with the others, correct it with the individual Foundation A, B or C liquid rather than increasing the ABC+ dose.
Suitable for, and not suitable for
- Suitable for: larger reef aquariums, frag systems or multi-tank setups with moderate, balanced calcium/alkalinity/magnesium demand run on a consistent dosing routine.
- Not suitable for: smaller or newer tanks that won't get through 5 kg before it's affected by long-term storage – the 1 kg tub is the better starting size. Also not suitable where one element consistently depletes faster than the others; dosing more ABC+ to correct it will overdose the other two.
Care and maintenance
Keep the tub sealed between uses – the powder is hygroscopic and will clump if it absorbs moisture from the air. Decant into smaller sealed containers if you dose from it daily, so the bulk of the tub is opened less often. Use a dry measuring scoop; a wet scoop introduces moisture into the remaining powder.
Safety
Store in a cool, dry place out of reach of children and pets. Avoid inhaling the fine powder when measuring doses, particularly when decanting the full 5 kg tub.
Goes well with
- Red Sea Reef Foundation Pro Multi Testing Kit – tests calcium, alkalinity and magnesium to confirm the elements are tracking together.
- Red Sea Reef Foundation ABC 3-Pack (liquid) – for correcting an individual element that's drifted out of proportion.
- Red Sea Skeletal Elements Foundation ABC+ 1kg – the smaller size for nano and newer reefs.
Warranty and delivery
Covered by Red Sea's standard consumer guarantee in addition to your rights under Australian Consumer Law. Ships standard courier as a single bulk tub – no cold chain or special handling required.
Common questions
Is the 5 kg tub worth it over buying 1 kg tubs?
Yes, if you'll use it within a reasonable time – it works out to roughly 41% less per gram than the 1 kg tub. For a smaller or newer system that doses lightly, the 1 kg tub is the more practical choice.
How long does 5 kg last on a large reef?
At the conservative end of the 1–2 g per 100 L dose range, 5 kg covers roughly 250,000 L of cumulative dosing – the actual time depends heavily on your tank's coral load and dosing frequency.
Can I use an auto-doser with ABC+ powder?
Not directly – ABC+ is a powder, not a liquid. Most reefers on daily dosing dissolve a batch in a bucket of RO/DI water first, then dose that solution through an auto-doser or by hand.
Will the powder clump in a 5 kg tub over time?
It can, if moisture gets in. Keep the lid sealed between uses and consider decanting into a smaller sealed container for day-to-day dosing rather than opening the full tub repeatedly.
What if calcium keeps dropping faster than alkalinity and magnesium?
Don't increase the ABC+ dose to compensate – that will overdose alkalinity and magnesium. Correct calcium on its own with Foundation A liquid instead.
