Monopotassium Phosphate

AKA MKP. The no-nonsense bloom booster for vibrant flowers and bigger fruit.
Clean, concentrated phosphorus and potassium in a fast-acting formula. MKP fuels flowering, root growth, and fruit, without added nitrogen or messy residue.

Fully water-soluble, zero-nitrogen formula (0-52-34 NPK)
Enhances flowering, fruiting, and root development
Dissolves instantly for use in soil, coco, and hydroponic systems
Use as a foliar spray, root drench, or hydro feed
Works with all Humboldts Secret nutrients

“This stuff is magic for my veggie garden — tomatoes are a month ahead of last year.”

$47.97

Packaging Update: You may receive previous or updated packaging during our transition. Same formula, same performance.

Interested in bulk buying or wholesale pricing? Contact us here.

Bigger blooms. Stronger roots. Better harvests.

MKP is the gardener’s secret when it’s time to push plants past “good enough.” This concentrated formula delivers phosphorus and potassium right when your plants demand it most — powering dense flowers, resilient roots, and fruit worth showing off.

"After one application, my tomatoes went crazy—we had to trim them back!"

No harsh additives: Nitrogen-free and safe for vegetables, herbs, and ornamentals

Visible results — fast: Customers report new blooms and fruit within a week

Trusted by thousands: A top-rated Humboldts Secret product with real gardener wins

Works in any setup: Ideal for hydroponic systems, soil, coco coir, drip irrigation, and foliar applications

Easy to use: No specialist knowledge needed. Mixes cleanly with water and integrates into any system

Supports flower & fruit development: Delivers targeted phosphorus and potassium when it matters most

No harsh additives: Nitrogen-free and safe for vegetables, herbs, and ornamentals

Visible results — fast: Customers report new blooms and fruit within a week

Trusted by thousands: A top-rated Humboldts Secret product with real gardener wins

Works in any setup: Ideal for hydroponic systems, soil, coco coir, drip irrigation, and foliar applications

Easy to use: No specialist knowledge needed. Mixes cleanly with water and integrates into any system

Supports flower & fruit development: Delivers targeted phosphorus and potassium when it matters most

See How It Works

What’s inside?

This is a pure, premium-grade PK fertilizer with no fillers, nitrogen, or mystery ingredients. It dissolves fully in water for fast absorption through your soil or leaves.
Monopotassium Phosphate (MKP 0-52-34)

52% Available Phosphate (P2O5)
34% Soluble Potash (K2O)

Whether you're growing strawberries, bougainvilleas, or citrus, this bloom booster supports optimal energy transfer and nutrient mobility.

Supports photosynthesis and flower development
Compatible with all Humboldts Secret nutrient systems
Safe for vegetables, ornamentals, and fruiting plants

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How to use Monopotassium Phosphate (4 basic steps).

1

Mix into water: Use 1 tsp per gallon for general watering or hydroponic systems. For foliar use, apply at 1/2 tsp per gallon.

2

Apply during bloom: Begin when you see early flower or fruit signs. Continue every 1–2 weeks as needed.

3

Use any method: Great for watering cans, drip systems, hydro reservoirs, or foliar sprayers.

4

Store smart: Keep in a resealable container. Product lasts season after season.

Concentrated power that unlocks fast, clean, measurable growth — respect the dose. No nutrient burn of second-guessing.

Power the bloom. Secure the yield.

Missing bloom nutrients at the right time is costing you flowers, fruit, and yield.
Monopotassium Phosphate helps your plants transition from growth to bloom smoothly — delivering vibrant flowers, healthier produce, and bigger harvests. Whether you’re growing tomatoes on the patio or citrus in the yard, this is a bloom booster that actually works.

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Whispers and shouts from gardeners’ wins.

Monopotassium Phosphate FAQ

This is one of the best hydroponic bloom boosters you can use. Humboldts Secret MKP is 100% water-soluble and mixes cleanly into nutrient reservoirs. It won’t clog lines or leave sediment, and works seamlessly with drip emitters, aeroponics, and recirculating hydro systems.

Absolutely, It’s frequently used on tomatoes, peppers, cucumbers, citrus, strawberries, and herbs. Humboldts Secret MKP contains no banned substances or synthetic growth regulators — just concentrated phosphorus and potassium in their most plant-available form.

Use every 1–2 weeks during flowering and fruiting stages. You’ll see better results when it’s used consistently through bloom, especially when paired with Humboldts Secret Base A & B. Watch for signs of new flower sets, fruit expansion, and improved vigor within days.

Yes, as long as each product is diluted into water first. Monopotassium Phosphate is compatible with the full Humboldts Secret lineup, and safe to use alongside micronutrients, calcium-magnesium products, and bloom enhancers like Flower Stacker.

The numbers refer to the NPK ratio: 0% nitrogen, 52% phosphorus, and 34% potassium. This specific blend is ideal for fruiting and flowering because it delivers what plants need most during late-stage growth, without promoting leafy or vegetative expansion.

Because it’s a highly concentrated dry formula, a little goes a long way. A 2 lb bag makes dozens of gallons of nutrient solution (enough to feed a full garden through the bloom cycle). Store it in a cool, dry place, and it’ll last season after season.

Any flowering or fruiting species — like tomatoes, beans, squash, melons, citrus, berries, bougainvillea, roses, or hibiscus — will benefit from MKP. It’s especially helpful for gardeners trying to boost flower set, encourage more fruiting, or improve bloom color and siz

The bloom waits for no one.

When the bloom window opens, your plants need more than hope — they need fuel. Monopotassium Phosphate is what experienced gardeners reach for when they need reliable, visible results, fast.
Thousands trust Humboldts Secret MKP to power their garden’s most important stage. It’s pure, potent, and proven.
Try it today — risk free.

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