Seachem Reef Pack NPK | 3 x 100mL Nitrogen + Phosphorus + Potassium Set

The Seachem Reef Pack NPK is a 3-bottle reef-supplementation kit that takes coral color and macroalgae growth to the next level. Each pack includes Reef Nitrogen™, Reef Phosphorus™, and Reef Potassium™ — three 100 mL bottles of targeted, marine-formulated supplements that let you dial in N, P, and K independently without dosing dissolved organics. Browse more reef care in our Saltwater Collection and pair with Water Test Kits so you can tune your dosing to actual tank readings.

Why This Pack

• Three reef essentials in one box — Reef Nitrogen, Reef Phosphorus, and Reef Potassium, each in a 100 mL bottle.
• Independent N, P, and K dosing — correct one limiting nutrient at a time instead of a one-size-fits-all blend.
• Targeted reef formula — Seachem’s reef-specific NPK line, not the freshwater Flourish version.
• Better color & growth — balanced N and P in particular drive deeper coral pigmentation and faster macroalgae growth.
• No dissolved organics — inorganic formulations avoid feeding nuisance algae or destabilizing skimmer performance.
• Trusted brand — backed by Seachem’s decades of marine-supplement chemistry.

What’s in the Pack

• Reef Nitrogen™ (100 mL) — raises nitrogen so it stays balanced with phosphorus, supporting optimal coral color and macroalgae growth. Use when nitrate (NO₃) is low or undetectable.
• Reef Phosphorus™ (100 mL) — boosts phosphorus for protein synthesis and metabolism in corals. Use when phosphate (PO₄) is low and growth/color has stalled.
• Reef Potassium™ (100 mL) — replenishes the third major macronutrient required for coral metabolism and pigmentation. Often depleted by GFO and heavy water changes.

How to Use

Always test before dosing. Reef Pack NPK is most effective when used with a reef test kit so you can target specific deficiencies rather than dose blindly.

• Test: Measure nitrate, phosphate, and potassium in your tank.
• Dose to target: Follow each bottle’s label dosing chart to raise the deficient parameter toward the recommended reef range.
• Re-test: Wait 24 hours, re-test, and adjust the next dose accordingly.
• Maintenance: Once parameters are stable, dose to replace daily uptake by corals and macroalgae.

Always read each individual bottle’s label for full dosing instructions and safety information.

Specifications

Recommended Pairings

• Reef Test Kits — nitrate, phosphate, and potassium test kits to dose accurately.
• Saltwater Refractometer — lock down salinity before tuning trace nutrients.
• More Reef Additives & Supplements — calcium, alkalinity, magnesium, and trace blends.
• Premium Salt Mixes — start with a quality salt mix for a stable baseline.
• Maintenance & Water Care — everything else your reef needs.

FAQ

Do I need to dose all three bottles every day?
Not necessarily. Test first — only dose the parameter that’s actually low. Many tanks need only one or two of the three.

Is this the same as the Plant Pack NPK?
No. The Plant Pack NPK uses Flourish Nitrogen, Phosphorus, and Potassium for freshwater planted tanks. Reef Pack NPK uses the marine-specific Reef Nitrogen, Reef Phosphorus, and Reef Potassium formulas for saltwater reef systems.

Will this raise nutrients too high in a low-nutrient reef?
Only if you over-dose. Reef Pack NPK is designed to correct low or undetectable nitrate, phosphate, and potassium levels — ULNS (ultra-low-nutrient systems) often need exactly this kind of targeted addition. Dose conservatively and test 24 hours later.

Can I use this in a fish-only saltwater tank?
Reef Pack NPK is designed for reef tanks with corals and macroalgae. Fish-only systems generally don’t need supplemental N, P, or K.

How long will the bottles last?
Depends entirely on tank size and dose, but at typical maintenance dosing on a 50–100 gallon reef, three 100 mL bottles will last several months.