DSR Reefing calculator

Step by step: choose what you want to adjust, enter your reading, target, and volume, and you get a dose suggestion that matches DSR rules: do not go faster per day than the limit allows.

This is a planning aid only. Confirm big changes with your own mentor, test often, and follow your product label (strength, density, and how the supplier means “ml” or “g”).

Expert calculator (compact)

All elements in one spreadsheet-style table — pure JavaScript in your browser, no form posts. Ideal for a quick overview of total correction doses (full gap in one step).

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CA

Move calcium toward the target range.

Target: between 420 and 460 ppm (DSR).

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KH

Adjust carbonate hardness (dKH).

Target: between 7 and 9 dKH (DSR).

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MG

Bring magnesium into the recommended range.

Target: between 1250 and 1400 ppm (DSR).

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K

Potassium offsets nitrate use — dose with care.

Target: between 380 and 420 ppm (DSR).

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SR

Keep strontium in line with calcium and alkalinity work.

Target: between 3 and 10 ppm (DSR).

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B

Boron: small, slow steps; a narrow room for change.

Target: between 3 and 5 ppm (DSR).

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I

Pick a target in the DSR band; raise the tank by at most 0.03 ppm per day.

Target: between 0.03 and 0.06 ppm (DSR). Maximum rise per day: 0.03 ppm.

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MN

DSR goal is at most 0.4 ppb; raise the tank by at most 0.1 ppb per day.

Target: max 0.4 ppb (DSR). Maximum rise per day: 0.1 ppb.

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PO4

Phosphate as food — do not force a large jump at once.

Target: between 0.02 and 0.10 ppm (DSR).

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NO3

Nitrate: feed slowly and stay in a safe band around the target.

Target: between 1 and 3 ppm (DSR).

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NaCl

Raise salinity with sodium chloride (max 2 ppt/day), or estimate saltwater to replace when salinity is too high (surplus correction %).

Measured and target salinity (ppt) are free inputs — this calculator does not enforce a band. Many reefs run ~33–34 ppt (DSR); if you are above target, use surplus correction % (default 35) to estimate litres to replace with lower-salinity water.

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FE

DSR Fe+ binds phosphate; build 20→40→60→80→100% of the 0.15 ppm/day max (0.03…0.15 ppm). Optional accelerated 12 h steps when PO4 is very high.

Peak Fe (ppm). Single dose max 0.15 ppm; measured Fe should stay below 0.25 ppm.

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ReefClear

Concentrated calcium carbonate + minerals for crystal-clear, decoloured water, stable pH support, and flocculation of fines and organics.

1.25 g per 100 L per application. Maintenance: 1× per week. Decolouring: same dose, at most 3× per week.

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MGSO4

Set aside one batch of MgSO₄ for your sulfate correction (ICP-based formula), then use the daily table for Mg: each dose is pure-Mg math ×1.21 in grams from that stock until it is used up.

At most 50 ppm Mg rise per day. Sulfate: total MgSO₄ to set aside = (volume L / 1000) × ΔSO₄ × (246.482 / 32.06) g.

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