- Sku: 316
- Vendor: Seachem
Seachem Reef Advantage Calcium
Seachem Reef Advantage Calcium is a non-caustic ionic calcium blend that restores and maintains calcium at natural seawater levels, the foundation stony corals need to build their skeletons. Unlike kalkwasser (limewater), it stays in a safe pH range of 8.3 to 8.6, will not deplete magnesium, and, used as directed, will not pull down alkalinity. It also carries magnesium and strontium in proportionate ratios, so you maintain all three together. Browse our full range of reef additives and supplements and the rest of the Seachem lineup.
Why Reefers Use It
- Non-caustic. Holds a safe pH of 8.3 to 8.6, unlike the high pH of kalkwasser.
- Three elements at once. Maintains calcium along with magnesium and strontium in proportionate ratios.
- Gentle on your numbers. Will not deplete magnesium, and will not crash alkalinity when used as directed.
- Easy to dial in. Predictable calcium increase per dose makes it simple to hit your target.
How to Use
Dissolve 5 g (1 level teaspoon) in at least 250 mL (1 cup) of fresh water, then add it to the tank for every 150 litres (about 40 US gallons), twice a week. Each dose raises calcium by roughly 12 mg/L. Do not exceed 10 g per 150 L per day, and test calcium every couple of weeks to adjust the amount or frequency. Do not mix Reef Advantage Calcium directly with a carbonate or alkalinity supplement; add them on alternate days or at least 30 minutes apart.
Choose Your Size
| Size | Best for |
|---|---|
| 250 g | nano and single reef tanks |
| 500 g | a single reef tank, regular dosing |
| 1 kg | larger reefs and fish rooms |
Specifications
| Brand | Seachem |
| Type | Non-caustic reef calcium supplement |
| pH | 8.3 to 8.6 (non-caustic, unlike kalkwasser) |
| Contains | Ionic calcium with magnesium and strontium (Ca:Mg:Sr 100:5:0.1) |
| Raises | About 12 mg/L calcium per 5 g dose in 150 L |
| Form | Powder (measuring scoop included) |
| Water type | Reef and saltwater only |
| Dose | 5 g (1 tsp) per 150 L (about 40 gal) twice weekly, dissolved first |
| Sizes | 250 g, 500 g, 1 kg |
Recommended Pairings
- Seachem Reef Buffer to maintain alkalinity, the partner to calcium in coral growth.
- Calcium and alkalinity test kits so you can dose to your numbers.
- More reef additives and supplements to round out magnesium and trace elements.
- Saltwater livestock and supplies for the rest of your reef.
FAQ
How is this different from kalkwasser?
Reef Advantage Calcium is non-caustic, so it will not spike pH the way limewater can. It also will not deplete magnesium and includes magnesium and strontium in the mix.
Can I mix it with my alkalinity supplement?
No. Never combine calcium and carbonate supplements directly. Dose them on alternate days or at least 30 minutes apart so they do not react.
Do I need to dissolve the powder first?
Yes. Dissolve each dose in at least a cup of fresh water before adding it to the tank.
What calcium level should I aim for?
Keep calcium in the natural seawater range, roughly 400 to 450 ppm, and test regularly to dose to that target.
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Seachem Reef Advantage Calcium
