Is liquid kelp profitable to sell on Amazon United States?

The niche generates $67K/yr across 16 tracked products. 2 of 2 products launched in the last 360 days are still selling. 90-day search growth is +162.8%. Flapen's verdict: Worth a look (56/100).

How competitive is the liquid kelp niche?

11 brands and 16 sellers compete. The top 5 products take 76% of clicks and top 5 brands hold 91% of demand.

What do buyers complain about in liquid kelp?

Top complaints mined from reviews: Value For Money, Plant Growth, Smell. The return rate is 0.4%.

When does demand for liquid kelp peak?

Demand peaks in Apr–May–Jun–Jul; the busiest month runs 4.3× the quietest.

What does it cost to enter the liquid kelp niche?

Listings span $11.84–$40.30; the average listing price is $24.61 (sweet spot $15–$100). The average incumbent carries 2,155 reviews — the moat a new listing must climb.

liquid kelp

Worth a look

Shows low returns (0.4%), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.

Returns

Incredible0.4%

return rate — above 5% kills the launch gate

Growth

Incredible+162.8%

90-day search growth — must beat 0% to launch

Avg price

Incredible$24.61

avg listing price — sweet spot $15–$100

Conversion

Great11.8%

search→purchase rate — share of searches ending in a sale

Price range

Great$11.84–$40.30

cheapest to priciest tracked listing — scored on the share inside $15–$100

Review moat

Okay2,155.13

avg incumbent reviews — the moat a new listing must climb

Quality gap

Okay4.6★

avg incumbent rating — lower means beatable quality

Brand share

Bad91%

top-5 brand share — brand-locked demand

Competition

Bad76%

top-5 click share — a locked-up shelf

Market size

Bad$67K

$67K/yr · 23K searches

Signals Trending

According to Flapen's Amazon United States niche tracking, liquid kelp is a $67K/yr Amazon United States market (23K searches/yr). The top 5 brands hold 91% of demand. Demand peaks in Apr–May–Jun–Jul. Verdict: Worth a look — 56/100.

Data updated Jul 15, 2026 · scored weekly · How we score niches

liquid kelp market data

Units sold / yr: 2K–3K; avg 100–250/product
Revenue / yr: $49K–$62K; units × avg price
Conversion rate: 11.8%
Avg BSR: #688
Page quality: 0%
Prime: 100%
Sponsored: 81%
Out of stock: 2.9%
Avg brand age: 87 months
Avg seller age: 161 days

Competition & brand share

The top 5 products capture 76% of clicks — a locked-up shelf that new listings rarely crack.

Brands

11 rising

Sellers

Top-5 brand share

91%

Top 20: 100%

Top-5 click share

76%

Top 20: 100%

Open market

Bloom City40%
GS Plant Foods37%
Blue Planet Nutrients9%
TPS NUTRIENTS2%
Smart Grower2%
Neptune's Harvest2%
Open — no brand owns it (5 brands, 7%)

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — +162.8% search growth over the last 90 days.

Peak months: Apr, May, Jun, Jul · busiest ÷ quietest = 4.3×

Open Trend

Top liquid kelp products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 16 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

GS Plant Foods Liquid Kelp Fertilizer Suitable for Organic Growing OMRI Listed Seaweed Concentrate for Lawns Gardens & Soil - 1 Gallon (Makes Up To 800+ Gallons)

GS Plant Foods$39.374.6★3,436 rev

Bloom City Seaweed and Kelp Fertilizer Liquid Seaweed Supplement for Stronger Roots Faster Growth & Improved Stress Tolerance 32 oz

Bloom City$19.204.6★5,473 rev

Bloom City Seaweed and Kelp Fertilizer Liquid Seaweed Supplement for Stronger Roots Faster Growth & Improved Stress Tolerance 8 oz

Bloom City$12.324.6★5,473 rev

GS Plant Foods Liquid Kelp Fertilizer Suitable for Organic Growing OMRI Listed Seaweed Concentrate for Flowers Gardens Vegetables & Soil - 1 Quart (Makes Up to 200+ Gallons)

GS Plant Foods$19.784.6★82 rev

Liquid Kelp Seaweed Fertilizer Concentrate - Blue Planet Nutrients Ascophyllum Nodosum Liquid Seaweed Supplement - Makes 470 Gallons - Quart (32 oz)

Blue Planet Nutrients$20.124.7★3,620 rev

Newest

by launch date

KelpEdge Organic Liquid Kelp Plant Supplement- Seaweed Extract Concentrated Fertilizer Booster OMRI Listed - Boosts Roots Growth & Blooms for Gardens Lawns Veggies Hydro & All Plants

KelpEdge$28.7310 rev

3mo ago

Grow Queen Organic Liquid Kelp & Seaweed Extract Prop Drop (Ecklonia Maxima) Root + Plant Growth Hormone & Root Plant Food for Water Propagation Hydroponics & Soil 8oz 55 Gallons

Grow Queen$18.74140 rev

8mo ago

Organic Sea Kelp Fertilizer for Plants Water-Soluble Makes 50 Gallons Kelp Meal Concentrate Plant Food for Indoor Gardens Hydroponics Vegetables Houseplants - Smart Grower - 2oz Bag

Smart Grower$19.56308 rev

1y ago

Nordic Kelp Boost Liquid - Perfect Plants (1 Gallon)

PERFECT PLANTS$24.8139 rev

1y ago

Seaweed Fertilizer Organic Kelp Plant Food for All Plants Boosts Nutrient Uptake for a Lush Vibrant Garden 8 oz

TPS NUTRIENTS$11.84127 rev

2y ago

What buyers say about liquid kelp

What buyers praise and complain about, mined from review topics.

What buyers love

Plant Growth58%

“Great plant growth”

Quality-Overall12%

“Great affordable products quality company”

Value For Money6%

“Good value”

Smell6%

“Doesnt stink”

Ease Of Use5%

“Easy to use”

Advertised Vs Actual Product2%

“Worked as advertised”

Strength2%

“Effective”

Instructions/User Manual/Troubleshooting2%

“follow instruction”

Spray/Flow2%

“I also like using it as a foliar spray”

Color1%

“And green”

What buyers complain about

Value For Money21%

“This stuff is a bit pricey”

Plant Growth15%

“Here is my honest breakdown after using it for a full growing season: The Pros: The 7-Day Turnaround: I had a couple of stunted”

Smell13%

“Smelly”

Quality-Overall6%

“Trash”

Size-Overall6%

“This was a very small package”

Thickness6%

“Very thin, diluted kelp mixture”

Hard Feel3%

“some of the plants seem hardier than they've ever been”

Color2%

“The color has dark appearance once diluted in the water”

Ease Of Cleaning2%

“was always messy to mix up”

Top return reasons

Leak-Proof34%

Size-Overall13%

Advertised Vs Actual Product12%

Functionality-Overall11%

Value For Money9%

Smell5%

Plant Growth4%

Defective Material/Parts2%

Product Condition1%

Contamination1%

Common questions

Is liquid kelp profitable to sell on Amazon United States?: The niche generates $67K/yr across 16 tracked products. 2 of 2 products launched in the last 360 days are still selling. 90-day search growth is +162.8%. Flapen's verdict: Worth a look (56/100).
How competitive is the liquid kelp niche?: 11 brands and 16 sellers compete. The top 5 products take 76% of clicks and top 5 brands hold 91% of demand.
What do buyers complain about in liquid kelp?: Top complaints mined from reviews: Value For Money, Plant Growth, Smell. The return rate is 0.4%.
When does demand for liquid kelp peak?: Demand peaks in Apr–May–Jun–Jul; the busiest month runs 4.3× the quietest.
What does it cost to enter the liquid kelp niche?: Listings span $11.84–$40.30; the average listing price is $24.61 (sweet spot $15–$100). The average incumbent carries 2,155 reviews — the moat a new listing must climb.