Precision Roots

Supply

Buy in this order.

Meters before nutrients. Nutrients before plumbing. Plumbing before lights. Specs, not a shopping channel.

  1. 01A pH meter you can calibrate, plus storage and pH 4 / 7 solutions.
  2. 02An EC meter (mS/cm). Combo pens are fine if they take proper calibration fluid.
  3. 03pH down (phosphoric) and a two-part hydroponic A/B. Nothing else in week one.
  4. 04Then the system that matches the crop — not the light, not the tent.
  5. 05Lights last, sized to a PPFD target, not a wattage brag.

The bench

What sits next to the tank

  • pH meter

    Calibratable, storage cap, pH 4 and 7 solutions

    A meter you cannot calibrate is a random number generator.

  • EC meter

    Reads mS/cm (or converts cleanly). Not a mystery PPM scale.

    500 and 700 PPM scales disagree. Millisiemens do not.

  • pH down

    Phosphoric acid, horticultural grade

    Hard tap water will climb. Nitric is an option later; phosphoric is the starter.

  • Two-part A/B

    Complete hydroponic, calcium in A, sulphates/phosphates in B

    One-part ‘grow juice’ precipitates. Two-part exists for a reason.

  • Syringes or a measuring cylinder

    ml, not a kitchen spoon

    The mixer in Tools is an estimate. The cylinder is the dose.

  • Notebook or the Bench Log

    Date, EC, pH, one note

    The protocol is a notebook. Hardware is secondary.

System kits

Pick the architecture, then the hardware.

Kratky jar

First lettuce or basil. No pump. Learn the air gap.

£25–40 plus meters

  • Opaque container 4–10 L

    Light-tight lid, hole for a 75 mm net pot

    Light in the tank is algae. Paint or wrap if it is translucent.

  • Net pots + rockwool or foam collar

    75 mm pots, sterile plugs

    The cube kisses the solution on day one, then hangs as the waterline drops.

  • Starter solution

    Complete two-part, mixed to 1.0–1.2 mS

    You do not top up. The whole crop has to live in this fill.

Consumables

What you will re-order

  • Calibration fluid

    pH 4, pH 7, EC 1.41 or 2.76

    Monthly, or whenever a reading looks clever.

  • Plugs

    Rockwool, coco, or foam — sterile, not garden compost

    Soil in a hydro tank is a pathogen courier.

  • Seed of one cultivar

    Named, pelleted if you can get it

    Mixed ‘salad seed’ hides whether the protocol is working.

  • Oxidiser for clean-down

    Food-safe hydrogen peroxide or a horticultural disinfectant

    Between cycles. Not a weekly personality.

Do not buy

The YouTube trolley

  • Uncalibrated supermarket moisture pens and ‘3-in-1 soil meters’.
  • Cal-Mag as a first bottle. Fix the recipe and the pH first.
  • Bloom boosters, PK 13/14, and anything that only adds potassium.
  • Clear reservoirs left in daylight. Algae is not a nutrient.
  • Aquarium air stones on a 40 L DWC — undersized, they die, roots follow.
  • NFT gutters for tomatoes. Architecture first.

Ask for millisiemens, food-safe plastics, and a chelate that matches your tap. If they lead with a bloom bottle, leave.

Named kit

What to ask for over the counter

  • Bluelab pH Pen + Conductivity Pen

    Calibratable. Buy the 4, 7 and 2.76 solutions with them.

    The industry standard meter. A cheap combo pen you cannot calibrate is not cheaper.

  • Growth Technology pH Down

    Phosphoric, horticultural grade

    UK bottle, known concentration. Not battery acid from a forum thread.

  • A complete two-part hydro A/B

    VitaLink Hydro, Terra Aquatica Flora, or Ionic — as long as Ca is in A

    Pick one line and stay on it. Mixing brands is how you invent a third recipe.

  • Nutriculture Gro-Tank

    NFT channel with lid, pump and tank as a set

    The UK NFT people have been doing this since before YouTube. Size to plant count, not to a photo.

  • Grodan starter cubes

    Sterile rockwool, 25–36 mm

    Consistent plugs. Soak and pH-adjust before sowing.

UK suppliers

Shops that stock the bench