Mills C4 1L bottle, 0.7-3-3 flower enhancer and bloom promoter
Mills C4 5L drum, flower enhancer and bloom promoter
Mills C4 1L bottle, 0.7-3-3 flower enhancer and bloom promoter
Mills C4 5L drum, flower enhancer and bloom promoter

C4 by Mills Nutrients — Early to Mid Bloom Stimulant

MN-ADD-C4-1L

$84.95
/
Tax included. Shipping calculated at checkout.

Bloom stimulant for early to mid flower that feeds carbohydrates, amino acids and trace minerals to developing flowers. Pair it with Basis A&B.

Size
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Pairs well with

C4 is the Mills bloom stimulant for early to mid flower. It is a blend of carbohydrates, macro and micro nutrients, trace minerals, L-amino acids and bio-stimulants, made to help plants move energy and nutrients into developing flowers and fruit. Mills says it encourages the plant's own oil and sugar production. NPK is 0.7-3-3. On the Mills chart it runs from bloom week 2 to week 6 at 0.5 to 2ml per litre, overlapping Ultimate PK for the last two of those weeks. It is an additive for flowering and fruiting plants, so it goes on top of Basis A&B, not instead of it.

Built for the build-up weeksC4 covers bloom weeks 2 to 6, the stretch where flower sites set and fill. It is not a late-flower PK hammer.
Carbohydrates plus mineralsSugars, amino acids and trace minerals in one bottle, instead of stacking a carb additive on top of a separate bloom booster.
Gentle on the ECAt 0.7-3-3 and 0.5 to 2ml per litre, C4 adds bloom support without blowing your EC past the Mills targets.
Clean handover to Ultimate PKThe chart overlaps C4 and Ultimate PK in bloom weeks 5 and 6, so there is no gap and no guessing when to switch.
Tap or RO dosesMills gives separate C4 rates for tap and RO water, so you are not working from one number that suits nobody.
Any mediumRuns in hydro, coco and soil alongside the rest of the Mills program.

Specifications
Brand: Mills Nutrients
Product: C4 bloom stimulant
NPK: 0.7-3-3
Key ingredients: Carbohydrates, macro and micro nutrients, trace minerals, L-amino acids, bio-stimulants
Sizes: 1L and 5L
Use: Bloom weeks 2 to 6
Dose: 0.5 to 1.5ml per litre (tap), 1 to 2ml per litre (RO)
Use with: Mills Basis A&B, then Ultimate PK from bloom week 5
Growing media: Hydro, coco and soil
Made in: Holland

Grower's Tip
  • Bring C4 in at bloom week 2, the same week Start-R finishes. Ramp it, do not jump straight to the top dose.
  • C4 goes in after Basis A and Basis B. Stir well before adding Ultimate PK on the weeks they overlap.
  • Carbohydrate additives feed whatever lives in your reservoir as well as your plants. Keep tanks cool, covered and changed on schedule.
  • Stop C4 after bloom week 6. From week 7 the Mills chart runs Ultimate PK on its own to the finish.
  • Meter after mixing. C4 is mild on EC, but the overlap weeks with Ultimate PK sit at the top of the Mills range at 2.6 to 2.8.

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

C4 dose from the Mills chart (ml per litre)

Water Bloom wk 2 Bloom wk 3 Bloom wk 4 Bloom wk 5 Bloom wk 6
Tap (EC 0.7) 0.5 1 1.5 1.5 1.5
RO (EC 0.0) 1 2 2 2 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 using C4?

At bloom week 2. The Mills chart starts C4 at 0.5ml per litre on tap water (1ml on RO) and builds it up over the next two weeks.

Can I use C4 and Ultimate PK together?

Yes. Mills runs them together in bloom weeks 5 and 6, then drops C4 and carries on with Ultimate PK alone.

Can I use C4 without Basis A&B?

No. C4 is an additive with an NPK of 0.7-3-3. It needs a full base nutrient underneath it, and Mills built it around Basis A&B.

Is C4 only for flowering plants?

Yes. Mills designed C4 for flowering and fruiting plants in bloom. It has no place in the growth weeks.

Does C4 work in soil and coco?

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

Which size should I buy?

At 0.5 to 2ml per litre for five weeks, the 1L suits a tent or two. The 5L is the better buy for bigger reservoirs or back-to-back runs.

Select Size

Feed the flowers while they build

Mills C4 for bloom weeks 2 to 6. Free shipping over $499*.

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