Plagron PK 13-14 — Concentrated Phosphorus Potassium Booster for Flowering
Best for: Growers looking to dial in flowering performance without paying premium prices for all-in-one boosters
Our thoughts
A focused, no-nonsense phosphorus potassium booster that does exactly one job and does it well. Plagron PK 13-14 is mineral-based, highly concentrated, and sits in that sweet spot where you get serious performance at a fraction of the cost of multi-function alternatives. One growers come back to time and again.
Plagron PK 13-14 is a liquid mineral flowering enhancer formulated to boost phosphorus and potassium during the latter half of your growing cycle. It's a straightforward, concentrated booster designed to support denser foliage development, stronger finishing, and better yields. No added complexity, no marketing fluff — just the minerals plants need when they're in full flowering mode. As a mineral formula, nutrients are absorbed rapidly, giving you visible results week to week.
How it compares
PK 13-14 sits in the focused booster category — it does one thing brilliantly.
- Higher phosphorus and potassium concentration than entry-level boosters like General Hydroponics KoolBloom (which runs 0-10-10)
- Significantly cheaper than all-in-one products like Plagron Green Sensation, which combine PK with additives you may not need
- Mineral-based for quick absorption, unlike organic boosters which work slower
- Chlorine-free and ballast-free — cleaner formula, less waste
If you know what you're doing with nutrients and want the best bang for your budget, this outperforms pricier alternatives.
Usage guidance
PK 13-14 is designed for use during the flowering phase and works alongside your base nutrients.
Timing
Start from week 3–4 of flowering (roughly 3–4 weeks after switching to 12-hour light cycles). Continue until one week before harvest. The longer you run it, the more densely foliage develops.
Dosage
Apply at 2ml per litre of water (1:500 ratio). This is a concentrated product — stick to the dose. It's easy to overfeed if you're heavy-handed. If you notice foliage becoming too thick or nutrient stress appearing, dial it back to 1.5ml/l or apply every other feed instead of every watering.
Compatibility
Works with any base nutrient line (Plagron, Canna, Terra, etc.), but don't combine with other PK boosters or multi-function bloom products like Green Sensation. Adding PK on top of PK will cause problems. Check your base nutrient's P and K values first.
pH and EC
Maintain pH between 5.5 and 6.5. This product doesn't significantly move pH on its own. Mineral solutions store longer than organic alternatives, so you can prepare in advance without degradation.
Technical specifications
- NPK ratio: 0-13-14
- Phosphorus (P2O5): 13% (160g/L)
- Potassium (K2O): 14% (170g/L)
- Form: Liquid, transparent
- Mineral type: Mineral fertiliser (fast-acting)
- Chlorine content: Chlorine-free
- Ballast: Ballast-free
- Application rate: 2ml per 1 litre water
- Recommended pH: 5.5–6.5
- Available sizes: 1L, 5L, 20L
Who this is for
- Growers using coco coir, perlite, or light soil mixes where mineral uptake is fast and precise control matters
- Experienced growers who understand base nutrients and want to add focused PK support without complexity
- Anyone running hydroponic or semi-hydroponic systems where quick nutrient response is essential
- Growers managing tight budgets without compromising on performance or yield quality
- Operators running multiple rooms or frequent crop rotations where cost per cycle adds up
This is not a standalone product or a beginner's tool. It works best alongside a proper base nutrient programme and assumes you understand how to measure EC, read plant response, and adjust accordingly.
Our take
Plagron PK 13-14 is a straightforward, high-concentration flowering booster that delivers results without the premium price tag. It's one growers trust because it works reliably, stores well, and costs significantly less than multi-function alternatives.
Good time to buy this while clearance stock lasts. If you're running a flowering programme and want to tighten foliage density and yield without overcomplicating your nutrient schedule, worth picking up.
