Mills Ultimate PK 1L bottle, 0-7-6 ripening promoter
Mills Ultimate PK 5L drum, 0-7-6 ripening promoter
Mills Ultimate PK 1L bottle, 0-7-6 ripening promoter
Mills Ultimate PK 5L drum, 0-7-6 ripening promoter

Ultimate PK by Mills Nutrients — Phosphite Late-Bloom Booster

MN-ADD-PK-1L

$84.95
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Tax included. Shipping calculated at checkout.

Phosphite-based PK booster for late flower, built to bulk, harden and ripen. Joins C4 at bloom week 5 and carries the run to the finish.

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Pairs well with

Ultimate PK is the Mills booster for the back end of flower. It is phosphite-based, carrying 7.4% phosphate and 6.6% potassium with trace boron, copper, iron, manganese, molybdenum and zinc, and Mills built it to bulk, harden and ripen flowers and fruit in the last weeks before harvest. On the Mills chart it joins C4 at bloom week 5, runs alongside it for two weeks, then carries the crop alone to week 9 at 2 to 3.5ml per litre. It is a PK booster, not a full feed, so it goes on top of Basis A&B. Mills says not to run it alongside another PK booster.

Phosphite, not just phosphateMills uses phosphite as its phosphorus source, a highly soluble form it picked for the late weeks when roots are working hardest.
Made for the finishBuilt as a hardener, bulker and ripener for the final weeks, not an all-of-bloom booster you run from day one.
Overlaps C4 on purposeThe chart runs C4 and Ultimate PK together in bloom weeks 5 and 6, so the feed never drops out between the two.
Trace elements includedBoron, copper, iron, manganese, molybdenum and zinc ride along with the P and K, so late flower is not running on PK alone.
Tap or RO dosesSeparate Mills rates for tap and RO water, peaking at 2.5ml (tap) or 3.5ml (RO) per litre in bloom weeks 7 and 8.
Any mediumRuns in hydro, coco and soil with the rest of the Mills program.

Specifications
Brand: Mills Nutrients
Product: Ultimate PK late-bloom booster
NPK: 0-7-6
Phosphate (P2O5): 7.4%
Potassium (K2O): 6.6%
Trace elements: Boron, copper, iron, manganese, molybdenum, zinc
Phosphorus source: Phosphite
Sizes: 1L and 5L
Use: Bloom weeks 5 to 9
Dose: 2 to 2.5ml per litre (tap), 2 to 3.5ml per litre (RO)
Use with: Mills Basis A&B, plus C4 in bloom weeks 5 and 6
Growing media: Hydro, coco and soil
Made in: Holland

Grower's Tip
  • One PK booster at a time. If you have another brand's PK in the cupboard, it stays there while Ultimate PK is in the tank.
  • Do not start it early. Mills brings it in at bloom week 5, and running PK hard from the first weeks of flower is how growers lock up their feed.
  • Ultimate PK goes in last, after Basis A, Basis B and C4. Stir between each one.
  • The two overlap weeks with C4 sit at the top of the Mills EC range, 2.6 to 2.8. Meter every mix.
  • Week 9 eases off to 2ml per litre with the base dropping too. Follow the taper rather than holding peak strength to the end.

How To Mix It
1Fill your reservoir or watering can with water.
2Add Vitalize if it is still on the chart for this week, then Basis A, then Basis B, stirring well after each.
3In bloom weeks 5 and 6, add C4 and stir.
4Shake the Ultimate PK, measure this week's dose from the chart below and stir it in.
5Check EC, then adjust pH to 5.5 to 6.5 last.

Ultimate PK dose from the Mills chart (ml per litre)

Water Bloom wk 5 Bloom wk 6 Bloom wk 7 Bloom wk 8 Bloom wk 9
Tap (EC 0.7) 2 2 2.5 2.5 2
RO (EC 0.0) 2 2 3.5 3.5 2

The full week-by-week program for every Mills product is on the Basis A&B page, or use the Mills nutrient calculator.

Pairs Well With

Frequently Asked Questions
When do I start Ultimate PK?

At bloom week 5 on the Mills chart, at 2ml per litre. It runs through to the last bloom week.

Can I use Ultimate PK with C4?

Yes. Mills runs both in bloom weeks 5 and 6, then drops C4 from week 7.

Can I use Ultimate PK with another brand's PK booster?

No. Mills says Ultimate PK is not to be used alongside other PK boosters. Doubling up stacks phosphorus and potassium past what the chart is built for.

What is the NPK of Ultimate PK?

0-7-6. It carries 7.4% phosphate (P2O5) and 6.6% potassium (K2O), with phosphite as the phosphorus source and a set of trace elements.

Can I use Ultimate PK without Basis A&B?

No. It is a PK booster with no nitrogen, so it needs a full base nutrient underneath it. Mills built it around Basis A&B.

Does Ultimate PK work in soil and coco?

Yes. It runs in hydro, coco and soil, the same as the rest of the Mills range.

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Finish the run properly

Phosphite-based PK for bloom weeks 5 to 9. Free shipping over $499*.

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