Seachem provides dosing instructions on all of our products, so you can always determine the correct dosage, but now it's even easier. With our dosage calculators, just enter a few known values and the calculator does the rest. Add this page to your smartphone home screen for easy access.

To reach your desired level use

g ( tspn)

Do not exceed 10 g/150 L (40 US gallons) per day

Considerations

Use Reef Status™ Calcium to test calcium levels.

We recommend a Ca level between 380-420 mg/L with an alkalinity between 3-6 meq/L (8-17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended levels or shocking corals and inverts. Each 5 g/150 L will raise calcium by about 12 mg/L.

DO NOT OVERDOSE

Do not exceed 10 g/150 L (40 US gallons) per day. Excess calcium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

g ( tspn)

Do not exceed 25 g/80 L (20 US gallons) per day

Considerations

Use Reef Status™ Magnesium to test magnesium levels

We recommend a magnesium level between 1200-1350 mg/L. Make large adjustments slowly to avoid overshooting intended level. Amount or frequency can be adjusted, but do not exceed 25 g/80 L per day. Dissolve in at least one cup of freshwater. Excess magnesium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement.

DO NOT OVERDOSE

Do not exceed 25 g/80 L (20 US gallons) per day. Excess magnesium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if magnesium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

g ( tspn)

Considerations

Use Reef Status™ Strontium to test strontium levels

We recommend a strontium level between 8-12 mg/L. It is advisable to make large adjustments slowly to avoid overshooting intended level. Excess strontium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement.

DO NOT OVERDOSE

Excess strontium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if strontium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

g ( tspn)

Considerations

Use MultiTest™ Marine pH & Alkalinity to test alkalinity levels.

Reef alkalinity should ideally be maintained at 3-6 meq/L (8-17 dKH). Reef Buffer™ will raise carbonate alkalinity; however, it is intended primarily for use as a buffer in a reef system where the maintenance of a pH of 8.3 is often difficult. When pH is not an issue, try Reef Builder™ or Reef Carbonate™

DO NOT OVERDOSE

Excess alkalinity may enhance the loss of calcium, magnesium, and strontium. Do not directly mix with any calcium, magnesium, or strontium supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

g ( tspn)

Do not exceed 12 g/150 L (40 US gallons) per day

Considerations

Use MultiTest™ Marine pH & Alkalinity to test alkalinity levels.

Reef alkalinity should ideally be maintained at 3-6 meq/L (8-17 dKH). Alkalinity should not be allowed to fall below 2 meq/L. It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts. Dissolve in at least one cup of freshwater.

DO NOT OVERDOSE

Do not exceed 12 g/150 L (40 US gallons) per day. Excess alkalinity may enhance the loss of calcium, magnesium, and strontium. Do not directly mix with any calcium, magnesium, or strontium supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

mL ( caps)

Do not exceed 15 mL per 80 L (20 US gallons) per day

Considerations

Use Reef Status™ Calcium to test calcium levels.

We recommend a Ca level between 380-420 mg/L with an alkalinity between 3-6 meq/L (8-17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts.

DO NOT OVERDOSE

Do not exceed 15 mL per 80 L (20 US gallons) per day. Excess calcium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

mL ( caps)

Do not exceed 1 meq/L per day

Considerations

Use MultiTest:™ Marine pH & Alkalinity to measure total alkalinity or Reef Status™ Magnesium, Carbonate & Borate to measure carbonate alkalinity.

Reef alkalinity should ideally be maintained at 3–6 meq/L (8–17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts. Each dose will raise alkalinity by about 0.25 meq/L.

DO NOT OVERDOSE

Excess alkalinity may enhance the loss of calcium, magnesium, and strontium. Do not directly mix with any calcium, magnesium, or strontium supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

mL ( caps)

Do not exceed 12.5 mL/80 L (20 US gallons)

Considerations

Use Reef Status™ Calcium to test calcium levels.

We recommend a Ca level between 380-420 mg/L with an alkalinity between 3-6 meq/L (8-17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts.

DO NOT OVERDOSE

Do not exceed 12.5 mL/80 L (20 US gallons). Excess calcium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement. Best if calcium & carbonate additives are added on alternate days or at least 30 minutes apart.

To reach your desired level use

mL ( caps)

Do not exceed 4 mL per 25 L (6.5 US gallons) per day

Considerations

Reef Fusion™ 1 & 2 are designed to be used together in a 1:1 ratio, but may be used separately to target specific ranges. When using this calculator to calculate a dose for calcium alone, keep in mind that a 1:1 dose with may produce undesired results.

Use Reef Status™ Calcium to test calcium levels.

We recommend a Ca level between 380-420 mg/L with an alkalinity between 3-6 meq/L (8-17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts.

DO NOT OVERDOSE

Do not exceed 4 mL per 25 L (6.5 US gallons) per day.

To reach your desired level use

mL ( caps)

Do not exceed 4 mL per 25 L (6.5 US gallons) per day

Considerations

Reef Fusion™ 1 & 2 are designed to be used together in a 1:1 ratio, but may be used separately to target specific ranges. When using this calculator to calculate a dose for calcium alone, keep in mind that a 1:1 dose with may produce undesired results.

Use MultiTest™ Marine pH & Alkalinity to test alkalinity levels.

We recommend a Ca level between 380-420 mg/L with an alkalinity between 3-6 meq/L (8-17 dKH). It is advisable to make large adjustments slowly to avoid overshooting intended level or shocking corals and inverts.

DO NOT OVERDOSE

Do not exceed 4 mL per 25 L (6.5 US gallons) per day.

To reach your desired level use

mL ( caps)

Considerations

Use MultiTest™ Iodine & Iodide to test idoide levels.

If necessary, adjust amount so that iodide reads 0.06–0.08 mg/L 6–12 hours after the last dose. Natural seawater has an iodine concentration of .06 mg/L; however, many corals and crustaceans can benefit from a slightly higher concentration. It is normal for iodide levels to decline after a few days. This results from utilization and chemical depletion. Therefore, frequency of use will vary with different reef tanks.

To reach your desired level use

mL ( caps)

Considerations

Use Reef Status™ Strontium to test strontium levels

We recommend a strontium level between 8-12 mg/L. It is advisable to make large adjustments slowly to avoid overshooting intended level. Excess strontium may enhance the loss of carbonate alkalinity. Do not directly mix with any carbonate supplement.

To reach your desired level use

grams ( tspns)

Considerations: 2 meq/L is equal to 5.6 dKH. If your test kit measures in dKH, divide your test kit reading by 2.8 to determine your current KH levels in meq/L. Do the same for desired KH.

To reach your desired level use

grams ( tbsp)

Considerations: Equilibrium can be added straight, although for optimum solubility we recommend mixing with ~ 1 L (1 qt.) of water (the resulting mixture will have a white opaque appearance). When this mixture is added to the aquarium it will impart a slight haze that should clear within 15–30 minutes.

Recommended Dose

mL ( caps)

Considerations: When using in conjunction with Flourish Trace™, dose on alternate days.

To reach your desired level use

mL ( caps)

Considerations: We recommend maintaining an Fe level of about 0.10 mg/L. Iron is used quickly, so you will want to initially exceed 0.10 mg/L in order to prevent iron levels from falling below that level. For smaller doses, please note that each cap thread is about 1 mL

To reach your desired level use

mL ( caps)

Considerations: If using a “nitrate equivalent” value for Current and Desired Nitrogen levels, divide the result by 5.

To reach your desired level use

mL ( caps)

Considerations: Use once or twice a week or as needed in response to signs of phosphorus deficiency (e.g. stunted growth, plant dark green). The ideal phosphate level will vary, but generally ranges from 0.15–1.0 mg/L. Use MultiTest™ Phosphate to monitor phosphate levels.

To reach your desired level use

mL ( caps)

Considerations: Repeat 2–3 times per week or as needed (in response to signs of potassium deficiency in older leaves which includes: chlorosis (yellowing), necrosis (death/browning), and weak stems and roots.

Recommended Dose

mL ( caps)

Considerations: Use twice a week. When using in conjunction with Flourish®, dose on alternate days.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

10 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

9 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

7 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.

Your project will require

10 kg bag(s) or
3.5 kg bag(s)

Find a Dealer

Note: The calculator will always round up. For example, you can't purchase 1.3 bags, so it will return 2 bags.

If you plan on varying the depth of your substrate, use an average depth as your desired substrate depth.