Comparison: Best Using Fish As A Fertilizer (Updated | Dec 1st)

The Alaska Fish Fertilizer (5-1-1) and Fertilome (5-1-1) both provide a balanced 5% nitrogen, 1% phosphate, and 1% potash, ideal for steady vegetative growth. Neptune’s Harvest offers a 2-3-1 ratio, which favors root development and blooming, while its 2-4-1 version leans more toward foliage vigor. The 1‑gallon organic fish emulsion lists a 2-3-1 ratio as well, but emphasizes a higher concentration of micronutrients and amino acids.

Traditional fish emulsions, such as the 1‑gallon organic fish emulsion, have a strong fishy smell that signals a genuine product, but it can be off‑putting for indoor use. Alaska’s 5‑1‑1 concentrate is deodorized with natural wintergreen, reducing the odor while retaining nutrient content. If you prefer a low‑odor option for indoor gardens, choose the deodorized Alaska fertilizer or Neptune’s Harvest, which uses a cold‑process that minimizes scent.

For indoor plants, the deodorized Alaska Fish Emulsion (5‑1‑1) and Central Garden Brands Fish Emul Fertilizer are safe choices because they won’t burn foliage and have milder aromas. Outdoor gardeners looking for high‑volume coverage may prefer the 1‑gallon organic fish emulsion or the 5‑gallon Alaska concentrate for larger beds and trees. Both types are labeled for indoor and outdoor use, but the smaller containers are more convenient for indoor pots.

Concentrated formulas like Alaska’s 5‑1‑1 (115 oz) and Fertilome (32 oz) require dilution—typically 1‑2 Tbsp per gallon of water for vegetables—so a little goes a long way, offering good cost per nutrient. Ready‑to‑use products such as Central Garden Brands (1 qt) and Neptune’s Harvest (18‑36 oz) are mixed at higher rates, which can be less economical for large gardens but convenient for quick applications. Compare the price per ounce and recommended usage to determine which gives the best value for your garden size.

Yes, the Alaska Fish Fertilizer (5‑1‑1) is OMRI listed, confirming it meets organic standards for certified organic farms. Central Garden Brands, Neptune’s Harvest, and the 1‑gallon organic fish emulsion also claim 100 % organic ingredients, though they are not specifically OMRI listed. If certification is important for your certification program, the Alaska product is the safest pick.

The 1‑gallon organic fish emulsion highlights a full spectrum of vitamins, amino acids, and micronutrients that boost flower production and color. Neptune’s Harvest 2‑3‑1 also emphasizes stronger, more colorful blooms and includes seaweed for additional trace elements. For gardeners focused on flower performance, the larger‑volume organic emulsion offers the richest micronutrient profile.

Bulk containers like Alaska’s 1‑gallon concentrate and the 1‑gallon organic fish emulsion provide the lowest cost per ounce, making them ideal for extensive vegetable beds or orchard trees. Smaller packages such as the 18‑oz Neptune’s Harvest or 32‑oz Fertilome are better for hobbyists or limited‑space gardens but have a higher per‑ounce price. Calculate the total amount of diluted solution you need per season to see which size offers the best savings.

API Leaf Zone products are specifically formulated for freshwater aquarium plants and should not be mixed with soil‑based fertilizers. Most fish emulsions, including Alaska, Central Garden Brands, and Neptune’s Harvest, are intended for soil applications and may harm aquatic life if added to tanks. For hydroponics, look for a water‑soluble, odor‑free formula like the deodorized Alaska concentrate, but always verify compatibility with your system’s nutrient schedule.