Comparison: Best Npk Of Fish Fertilizer (Updated | Dec 1st)
With so many options boasting different NPK ratios, it’s easy to feel overwhelmed. What’s the best blend for lush greens, strong roots, or vibrant blooms? We’ve dug into the science and tested real results to help you cut through the noise.
- Best for omri certified: Alaska Fish Fertilizer OMRI Listed 5-1-1
- Best for vitamin-rich formula: CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer
- Best for eco-friendly 2-3-1: 1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants
- Best for seedling power boost: FoxFarm Bush Doctor Wholly Mackerel Fish Fertilizer
- Best for odorless cold-processed: Neptune’s Harvest Fish Fertilizer 2-4-1
- Best for aquarium macro boost: Flora NPK – Liquid Macro Nutrient Fertilizer for Aquarium Plants (Nitrate
- Best for vigorous green growth: Fertilome (10612) Fish Emulsion Fertilizer 5-1-1 (32 oz)
- Best for wintergreen deodorized: Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon (Packaging may vary)
- Best for odorless growth boost: Fish Hydrolysate Fertilizer for Vegetables & Plants – NPK 2-3-2 Fish Emulsion for Lawn
- Best for large odorless formula: Neptune’s Harvest Fish Fertilizer 2-4-1
Product Comparison: Best Npk Of Fish Fertilizer
Alaska Fish Fertilizer OMRI Listed 5-1-1, 115 oz
- Fish-based fertilizer for use in vegetable, fruit, and flower gardens
- Excellent for use on flowers, trees, and other plants
- OMRI listed
- For organic gardening
- Great for all indoor and outdoor plants
- NPK 5-1-1 fish emulsion fertilizer
- Fish has been used as a natural source of plant nutrients for centuries
- Easy to use, just mix with water
CENTRAL GARDEN BRANDS 100099247 Fish Emul Fertilizer, 1 Quart
- Promotes healthy plant growth with 11 vitamins
- Can be used on all indoor and outdoor plants
- 100-percent organic
- Stimulates microorganisms
- Does not burn
1 Gallon Organic Fish Emulsion Fertilizer for Plants – Ideal Liquid Fish Fertilizer for Plants, Flowers, Fruits & Vegetables, 2-3-1 NPK – Sustainably Sourced and Hydrolyzed for Steady Growth
- ORGANIC FISH EMULSION FERTILIZER – Our liquid fish fertilizer is made from sustainably sourced fish emulsion and we use up all the parts that would otherwise go to waste. Using an environmentally conscious method, ingredients are refined fresh and 100% cold pressed to help retain all of the nutrients, vitamins, and amino acids needed to grow healthy plants.
- GROW PLANTS NATURALLY – This wonderfully organic alternative to synthetic fertilizer contains a 2-3-1 NPK ratio perfect for light and frequent applications. Promotes steady, healthy plant development throughout the growing season.
- ENRICHES SOIL – Helps build a strong foundation for your organic garden to thrive on! Use as an effective soil drench to improve fertility, structure, and encourage the growth of beneficial microorganisms like fungi in your garden’s soil.
- PRODUCE MORE – Get the most out of your fertilizer and your garden! This organic garden fertilizer helps to increase crop yields and flower blooms. Gentle enough to use as a foliar spray makes this the perfect fish fertilizer for plants, flowers, and vegetables.
- SMELL THE DIFFERENCE – This fertilizer smells like fish because it’s made from fish! Crafted with high-quality concentrated and undiluted hydrolyzed fish emulsion each bottle gives off a pungent fishy aroma. When compared, we see it like this – if it doesn’t smell, then it’s not real fish!
FoxFarm Bush Doctor Wholly Mackerel Fish Fertilizer, Fx14113 – Liquid Plant Nutrient for Seedlings, Transplants, and Vegetative Growth – NPK 3-1-0 (Pint)
- SEEDLING & TRANSPLANT VITALIZER: This fish plant food promotes root strength, making it perfect for nurturing young seedlings & transplanted plants. Its fast-acting formula ensures plants receive rapid nutrition, helping them establish robust foliage
- EFFECTIVE ROOT DRENCH APPLICATION: This fish fertilizer for plants is for root drench applications, allowing nutrient absorption through the roots. It ensures deeper nutrient penetration, enhancing plant resilience, during early growth stages
- ESSENTIAL GROWTH INGREDIENTS: Made with fish protein hydrolysate, molasses, and kelp, this fish emulsion fertilizer provides a mix of nutrients. Fish protein provides essential amino acids, molasses gives soil microbes, and kelp supports plane health
- EASY MIX FOR THRIVING PLANTS: Using fish plant fertilizer is a breeze, simply mix 1 tablespoon per gallon of fresh water and drench the soil thoroughly. For optimal results, apply every other week throughout the vegetative cycle until early fruiting
- TRUSTED FOXFARM QUALITY: From a brand known for sustainable and effective gardening solutions, Our fish hydrolysate fertilizer is a high-quality option for feeding your plants. Trust FoxFarm for products that support lively gardens and vibrant plants
Neptune’s Harvest Fish Fertilizer 2-4-1, 18 Ounce
- Neptune’s Harvest is an organic fertilizer made from fresh north Atlantic fish
- It is made by a unique cold process that protects the vitamins, amino acids, enzymes and growth hormones
- It also contains all the micro and macro nutrients naturally found in fish
- Unlike fish emulsions, Neptune’s Harvest retains the fish proteins and oils and has no unpleasant odor
Flora NPK – Liquid Macro Nutrient Fertilizer for Aquarium Plants (Nitrate, Phosphate, Potassium) – Boosts Growth and Color in Freshwater Tanks – Part of The Flora Nutrition Series – 16.9 fl oz
- Essential Macro Nutrients (N-P-K): Provides nitrate, phosphate, and potassium in the ideal ratio to fuel fast and healthy aquatic plant growth in freshwater aquariums.
- Improves Leaf Color and Strength: Enhances overall plant color, vitality, and structure with consistent macro nutrient delivery through the water column.
- Perfect for High-Tech and Low-Tech Tanks: Suitable for aquariums with or without CO2 injection and high lighting; adjust dosage to plant density and tank setup
- Liquid Alternative to Root Tabs: Distributes nutrients evenly to rooted and water-column feeders; ideal for use with aquatic plant soil or inert substrates.
- Part of the Flora Nutrition Series: Combine with Flora Micro, Flora Trace, and Carbon Boost for a complete 4-part aquarium plant care system
Fertilome (10612) Fish Emulsion Fertilizer 5-1-1 (32 oz)
- Develops deep green foliage, vigorous root systems and a solid plant structure
- Derived from fish soluble, can be used from indoor and outdoor. Can be used on plants and trees.
- Mixes with water and can be used by any convenient method of application. Shake well before use.
- 5-1-1 Fertilizer contains 5% Nitrogen, 1% Phosphate and 1% Soluble Potash.
- For plants mix 1-2 tbsp per 1 gal of water. For trees mix 4 tbsp per gal of water.
Alaska Fish Emulsion Fertilizer 5-1-1 Concentrate 1 Gallon (Packaging may vary)
- Will Not Burn
- Great for all plants
- Deodorized with Natural Wintergreen
- 5-1-1 fertilizer is an excellent source of organic plant nutrients
- Fish Fertilizer
Fish Hydrolysate Fertilizer for Vegetables & Plants – NPK 2-3-2 Fish Emulsion for Lawn, Flowers, Fruits & Vegetables in Garden or Farm (16 fl oz)
- Rich in amino acids and nutrients
- Natural and eco-friendly
- Boosts plant growth and vitality
- Works both as soil drench & foliar spray
- helps add organic matter to soil
- Will not burn plants, no bad odor
Neptune’s Harvest Fish Fertilizer 2-4-1, 36 Ounce
- Neptune’s Harvest is an organic fertilizer made from fresh north Atlantic fish
- It is made by a unique cold process that protects the vitamins, amino acids, enzymes and growth hormones
- It also contains all the micro and macro nutrients naturally found in fish
- Unlike fish emulsions, Neptune’s Harvest retains the fish proteins and oils and has no unpleasant odor
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Buying Guide
FAQs
What NPK ratio is best for general vegetable and flower gardening?
For most vegetable and flower beds a balanced 5-1-1 or 2-3-1 ratio works well, providing enough nitrogen for leafy growth while keeping phosphorus and potassium modest. A 5-1-1 formula, like Alaska Fish Fertilizer or Fertilome, is ideal for rapid foliage development. If you prefer a slightly lower nitrogen boost, the 2-3-1 ratio found in the 1‑gallon Organic Fish Emulsion supports steady growth without risking excess vegetative sprawl.
How do organic fish fertilizers compare to synthetic chemical fertilizers?
Organic fish fertilizers release nutrients slowly through natural amino acids, vitamins, and hormones, which improve soil biology and long‑term fertility. Synthetic fertilizers deliver nutrients instantly but can burn roots and often lack the microbial benefits of fish emulsions. Choosing fish‑based products, such as Neptune’s Harvest or FoxFarm Bush Doctor, gives you a gentler feeding schedule and better soil health over time.
Which fish fertilizer gives the best value per ounce?
The Alaska Fish Fertilizer (115 oz, 5‑1‑1) and the Alaska Fish Emulsion Concentrate (1 gal) provide the most nutrient per dollar, especially when diluted as recommended. Neptune’s Harvest 2‑4‑1 offers a premium cold‑process formula but is sold in smaller 18‑oz containers, making its cost per ounce higher. For budget‑friendly bulk buying, the larger 1‑gallon Organic Fish Emulsion (2‑3‑1) also delivers excellent value.
I’m sensitive to strong smells—are there fish fertilizers that are low‑odor?
Yes, several products are formulated to reduce the typical fishy scent. Alaska Fish Emulsion (5‑1‑1) is deodorized with natural wintergreen, and the 5‑1‑1 Fertilome blend is marketed as low‑odor. Neptune’s Harvest retains fish proteins but claims a milder aroma compared with standard emulsions, while the 1‑gallon Organic Fish Emulsion openly states it has a strong fish smell if you prefer a true‑fish product.
How should I apply fish fertilizer to seedlings versus mature plants?
For seedlings, use a very dilute solution—about ½ teaspoon per gallon of water—to avoid nitrogen burn and encourage gentle root development. Mature plants can handle a stronger mix, typically 1–2 tablespoons per gallon, applied as a soil drench every two weeks. Foliar sprays are also effective for flowering stages, especially with the 2‑3‑1 and 2‑3‑2 formulas that absorb quickly through leaf tissue.
What extra ingredients set some fish fertilizers apart?
FoxFarm Bush Doctor includes molasses and kelp, which feed beneficial microbes and improve overall plant vigor. The 1‑gallon Organic Fish Emulsion highlights a cold‑pressed, 100 % hydrolyzed fish process that preserves vitamins and amino acids. Neptune’s Harvest uses a unique cold‑process that retains fish oils and proteins, delivering micro‑nutrients that many plain emulsions lack.
Is a higher concentration product like Alaska Fish Emulsion worth the extra dilution steps?
Concentrated formulas let you customize nutrient strength for different growth stages, which can be more economical in the long run. However, they require careful measurement to avoid over‑feeding, especially on young plants. If you prefer a simple, ready‑to‑use option, pre‑diluted products such as the 5‑1‑1 115 oz bottle or the 2‑3‑1 1‑gallon Emulsion are more convenient.
Can I use fish fertilizer for indoor houseplants?
Absolutely—most fish fertilizers are safe for indoor use when diluted correctly. Products labeled for “all indoor and outdoor plants,” like Central Garden Brands Fish Emul and the 5‑1‑1 Fertilome, work well on foliage plants and herbs. Just ensure good ventilation if you choose a formula with a stronger odor, and apply the solution during a light watering to prevent leaf spotting.