PK · Phosphorus · potassium
Fuel the bulk.
Mid-to-late flower is when the plant wants phosphorus and potassium most — and a base feed rarely has enough. PK is a concentrated P-K boost for the weeks that put on weight.
Australian-made · 26 years in the US · N-P-K 0–19.5–21
Why it matters
Peak bloom runs hot.
In the bulk weeks the plant’s demand for phosphorus and potassium spikes past what most base feeds deliver. PK covers the gap.
Phosphorus
Powers flower development and energy transfer.
Potassium
Drives sugar movement, density and finish quality.
Concentrated boost
High P-K exactly when the plant demands it.
How PK works
Two elements, peak bloom.
A concentrated phosphorus-potassium boost for the bulk weeks.
Phosphorus (19.5) Flower fuel
Powers flower development and energy transfer in bud.
Potassium (21) Bulk & quality
Moves sugars, builds density and hardens the finish.
Peak-bloom timing Weeks 4–6
Slots into the window where demand runs highest.
Tops up the base Gap-filler
Covers the P-K a base feed alone runs short on.
Why growers add it
Base only vs. + PK.
Base feed only
✗
P and K run short in peak bloom.
✗
Bulk stalls below its potential.
✗
Density and finish suffer.
✗
The base can’t keep up with demand.
Base + PK
✓
A concentrated P-K surge on demand.
✓
Bulk driven through the key weeks.
✓
Denser, better-finished bud.
✓
Demand met, right on time.
A little goes a long way
1 L → 1,000 L
of finished feed at 1 ml/L — a concentrated boost for the weeks that decide weight.
Proof — label & MSDS
Straight off the label.
N – P – K
0 · 19.5 · 21
Type
Phosphorus potassium supplement
Dose
1 ml/L
Made in
Australia
Proprietary mineral + organic blend
100% biodegradable
pH 8–10
By Agricultural Organics, South Australia
N-P-K from the product label. Composition and properties from the manufacturer MSDS.
When to use it
Peak bloom. The bulk weeks.
Veg
Early flower
Mid flower
Peak bloom
Flush
Peak flower weeks, every feed1 ml/L
Soil / coco / hydroany medium
Final flushstop
Fuel the bulk.
Finish it dense.
Shop PK →
Or DM FEED CHART to @bloom_crew_nate for your full feed schedule.