Plagron Fish Force — Organic Growth Phase Supplement for Rapid Foliage Development
Best for: Growers wanting fast, visible greenery and strong plants during the vegetative stage without synthetic chemicals
Our thoughts
Fish Force is a proper organic growth booster that delivers results quickly. It's not a base nutrient—think of it as a weekly top-up that pushes your plants harder during veg. Week-long use and you'll see greener, stronger foliage. One growers rely on for mother plants and fast-starting seedlings.
Plagron Fish Force is a fish-based organic growth supplement designed to drive rapid foliage development during the vegetative stage. Packed with natural amino acids, seaweed extract, and a 3-5-2 NPK formula, it strengthens plants fast, builds resistance to pests and disease, and works as either a standard weekly feed or a quick foliar spray. This is a supplement, not a standalone nutrient—pair it with your base feed and watch your plants respond.
How it compares
Fish Force sits in the organic growth booster category, similar to BioBizz Alg-A-Mic but with a heavier nitrogen bias.
- Higher nitrogen than seaweed boosters—faster visible greenery
- Fully organic, no synthetic additives
- Works for soil, coco, and foliar application
- Weekly dosing vs. bi-weekly alternatives means faster results but more frequent feeding
- Not suitable for hydroponic systems—organic particles don't dissolve cleanly
Usage guidance
Fish Force is a weekly top-up during vegetative growth. Here's how to use it properly:
Standard feeding (soil or coco)
Dose at 10ml per litre of water, apply once weekly during the growth phase. Shake the bottle well—organic ingredients settle. The solution stays stable for up to 48 hours after mixing.
Foliar spray
Same 10ml per litre dilution. Spray top and bottom of leaves for quicker uptake if you need fast recovery from stress or visible results within days.
Mother plants
Treat weekly year-round to keep foliage thick, green, and disease-resistant.
Important notes
Fish emulsion has a strong smell—use outdoors or in well-ventilated spaces. Do not use in automated watering systems or hydroponic setups; organic particles can clog lines and aren't designed for closed-loop systems. Keep between 0°C and 35°C. Shake well before every use.
Technical specifications
- NPK: 3-5-2 (Nitrogen 3.1%, Phosphorus Pentoxide 6.6%, Potassium Oxide 1.9%)
- Form: Liquid
- pH: 3.6
- EC: 26 mS/cm
- Density: 1.14 g/mL
- Key ingredients: Fish protein, seaweed extract, amino acids, vitamins
- Available sizes: 500ml, 1 litre, 5 litre
- Dosage: 10ml per litre, weekly during growth phase
- Storage: 0–35°C, protect from frost and direct sunlight
Who this is for
- Soil and coco growers wanting organic growth supplements without synthetics
- Anyone running mother plants that need to stay strong and disease-resistant year-round
- Growers seeking visible, fast results during the vegetative stage
- Outdoor cultivators looking to build robust foliage before the flowering phase
- Budget-conscious growers—Fish Force delivers at a lower cost than branded alternatives
Not ideal for hydroponic systems, automated drip irrigation, or small indoor spaces where odour is a concern.
Our take
Fish Force is a no-nonsense organic booster that does exactly what it should—pushes green growth fast and keeps plants sturdy. It's been trusted by Plagron for over 30 years, priced properly, and works. The catch: it's a supplement, not a complete nutrient, and it stinks. Use it outdoors or in a ventilated space, pair it with a proper base feed, and you'll see why growers keep coming back to it.
Good time to buy while stock lasts. Worth picking up if you're serious about strong, fast vegetative growth.
