Salt Mix Needed
5.0 cups
Weight
3.1 lbs
PPT
35
Salt Mix Needed
5.0 cups
1400g / 3.09 lbs
Target PPT
35
Mix Time
20 min
Use RODI water, heat to 78°F, add salt slowly while stirring with a powerhead.
Suggested heater: 30W for 10 gal mixing container.
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Inputs
Result
10 gal × 0.5 cups/gal × (1.025 - 1.0)/0.025 = 5.0 cups. 5.0 × 280g = 1,400g.
Inputs
Result
50 × 0.53 × 1.04 = 27.6 cups. Weight: 27.6 × 280 = 7,718g (17.0 lbs).
Most salt mixes use about 1/2 cup (140g) per gallon to reach 1.025 specific gravity. Exact amounts vary by brand — always verify with a refractometer.
| Brand | Cups/Gallon | Target SG | Best For |
|---|---|---|---|
| Instant Ocean | 0.50 | 1.025 | Fish-only, FOWLR |
| Red Sea Coral Pro | 0.53 | 1.025 | Reef tanks, SPS |
| Fritz RPM | 0.52 | 1.025 | Mixed reef |
Most reef tanks target 1.025–1.026 specific gravity (35 ppt). Fish-only tanks can run 1.020–1.025. Consistency matters more than exact number.
Mix for a minimum of 2 hours with a powerhead, ideally 24 hours. This allows salts to fully dissolve, pH to stabilize, and temperature to equalize.
No. Tap water contains chlorine, chloramine, heavy metals, phosphates, and silicates that cause algae blooms and harm corals. Always use RODI (reverse osmosis deionized) water.
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Last Updated: Mar 19, 2026
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