Terra Aquatica TriPart FloraMicro HW — Hard Water Chelated Micronutrient Foundation
Best for: Hard water growers running the three-part TriPart system in hydroponics, coco, or soil
Our thoughts
FloraMicro HW is the foundation that keeps the entire TriPart system running clean on hard water. It's been trusted since the seventies and used by universities and research labs for good reason — it does exactly what it's supposed to do without surprises. If you're in a hard water area, this is the correct Micro to use. Get this right and the rest of your feed follows.
Terra Aquatica TriPart FloraMicro HW is the core micronutrient component of the three-part TriPart feeding system, specifically formulated for growers using hard water supplies. It provides essential trace elements—iron, manganese, zinc, copper, boron, and molybdenum—alongside complementary nitrogen and calcium, all in fully chelated form for maximum plant uptake. This is the stabilising foundation that the Grow and Bloom components build on. Get Micro right and the rest locks in place.
How it compares
This sits firmly in the modular, three-part nutrient category—a world away from one-part universal feeds.
- Specifically formulated to prevent lockout in hard water areas (over 70 mg/L calcium)
- Fully chelated micronutrients for superior bioavailability compared to non-chelated alternatives
- Gives you control to adjust Grow and Bloom ratios without reformulating the entire feed
- No need to buy separate CalMag or PK boosters—three bottles covers the entire cycle
- Scientific pedigree: used by universities, research labs, and NASA-backed testing since the 1970s
Competitors like Advanced Nutrients offer automatic pH balancing but charge more. FoxFarm is simpler but less customisable. TriPart gives you the balance between concentration and flexibility without the premium markup.
Usage guidance
Mixing order (critical)
Always add FloraMicro HW to your water first, stir thoroughly, then add Grow and Bloom separately. Never mix the three concentrates together directly—this causes precipitation and excessively high nutrient concentration.
Dosage rates
Add between 0.5ml and 2.0ml per litre of nutrient solution, depending on growth stage. Terra Aquatica recommend 0.2ml–1.6ml per litre across seedling to flowering.
Vegetative growth
Run higher Grow ratios with base Micro dosing to build leaf mass and root structure.
Flowering stage
Increase Bloom component while keeping Micro stable to support fruit and flower development without trace element deficiency.
System compatibility
Works across all hydroponic systems—DWC, NFT, ebb and flow—and equally clean in recirculating and run-to-waste setups. Also performs well in coco and soil-based growing.
Water type — critical
Use this HW (hard water) version only if your mains supply contains more than 70 mg/L calcium. Soft water or RO users should select the SW (soft water) formulation instead. Running the wrong version will either lock out calcium or undersupply it.
Technical specifications
- Product type: Three-part liquid nutrient base component
- Formulation: Hard water variant (HW)
- Total Nitrogen (N): 5.0% (3.5% nitrate, 1.5% ammoniacal)
- Potassium oxide (K₂O): 4%
- Calcium oxide (CaO): 1.4%
- Micronutrients (all chelated):
- Iron (Fe): 0.12% (6% EDDHA, 11% PDTA)
- Manganese (Mn): 0.05% (EDTA)
- Zinc (Zn): 0.015% (EDTA)
- Copper (Cu): 0.01% (EDTA)
- Boron (B): 0.01%
- Molybdenum (Mo): 0.004%
- pH stabilisation: Organic buffers included
- Available sizes: 1L, 5L, 10L
- Format: Liquid concentrate
Who this is for
- Growers in hard water areas of the UK who need calcium-balanced formulations
- Experienced hydro growers wanting full control over nutrient ratios across growth stages
- Commercial setups and research operations (proven track record in labs and universities)
- Anyone running multiple plants or systems where three-part dosing saves money vs buying separate CalMag and PK boosters
- Growers who want scientific credibility and proven longevity—TriPart has been trusted since the 1970s
Not for growers who want simplicity over control. If you prefer one-part feeds, look elsewhere. TriPart rewards users who take time to understand their plants' needs.
Our take
FloraMicro HW is reliable foundation work. Properly formulated for hard water, fully chelated for uptake, and backed by decades of real-world use. It doesn't make wild promises—it just works predictably once you've dialled your ratios in.
If you're running the TriPart system on hard water, this is the correct Micro to use. Does exactly what it should, day in, day out. Worth picking up while stock lasts.
