Seachem Reef Complete
Cost per litre
1.2c
Water type
Marine + Reef
Seachem Reef Complete
Concentrated calcium that won't spike your pH. Seachem Reef Complete is a 160,000 mg/L ionic calcium blend that also supplies magnesium and strontium in the ratio natural seawater carries them — the three elements hard corals, clams and coralline algae draw down fastest.
Key features
- Concentrated ionic calcium at 155–160 mg per gram of product.
- Magnesium and strontium included, in a 100:5:0.1 ratio to calcium — matching natural seawater rather than calcium alone.
- Won't spike pH when dosed as directed.
- Suits SPS, LPS, clams and coralline algae, all of which draw calcium down quickly.
- 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 | $12.95 | 5 mL per 80 L, twice weekly | 1,600 L |
| 250 mL | $19.95 | 5 mL per 80 L, twice weekly | 4,000 L |
| 500 mL | $22.95 | 5 mL per 80 L, twice weekly | 8,000 L |
Target calcium is 380–420 mg/L, with alkalinity held at 3–6 meq/L (8–17 dKH) alongside it.
Ingredients
| Component | Amount per gram |
|---|---|
| Calcium | 155–160 mg |
| Magnesium | 8 mg minimum |
| Strontium | 0.16 mg minimum |
Active constituents: calcium chloride, magnesium chloride, strontium chloride.
Suitable for, and not suitable for
- Suitable for reef aquariums with hard corals, clams or coralline algae drawing calcium down.
- Not a substitute for testing — dose to a calcium test result, not on a fixed schedule.
- Not for freshwater aquariums.
Dosage and directions
Beginner dose: 5 mL per 80 L, twice weekly. Check calcium every fortnight. Each 5 mL/80 L dose raises calcium by roughly 10 mg/L; do not exceed 12.5 mL per 80 L in a single day.
For a continuous dosing pump, Seachem publishes the formula m = vc/160, where m is mL of Reef Complete, v is tank volume in litres and c is the mg/L calcium rise wanted.
Cost per litre at every pack size works out under 1c, calculated on the standard dose:
| 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
- Causes serious eye irritation — avoid contact with skin and eyes, and keep out of reach of children.
- Do not exceed 12.5 mL per 80 L per day. Excess calcium can accelerate the loss of carbonate alkalinity.
- Do not mix directly with a carbonate or alkalinity supplement — dose on alternate days or space doses at least 30 minutes apart.
Care and storage
Keep the cap sealed between doses and store out of direct sunlight at room temperature.
Goes well with
- Seachem Reef Buffer — for pH alongside calcium.
- Seachem Reef Carbonate or Seachem Reef Builder — the alkalinity half of the balance.
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
Can I dose Reef Complete and an alkalinity supplement on the same day?
Yes, but not at the same time — space the two doses at least 30 minutes apart, or alternate days, so the calcium and carbonate don't react before they've mixed through the tank.
Will Reef Complete affect my pH?
Not when dosed as directed — it's formulated to add calcium without the pH swing a straight calcium chloride solution can cause.
What's the ratio of magnesium and strontium to calcium?
Roughly 100:5:0.1 — calcium, magnesium, strontium — matching the balance found in natural seawater.
Is this reef safe for SPS and clams?
Yes — it's formulated specifically for the elements SPS, LPS, clams and coralline algae draw down fastest.
