Terra Aquatica TriPart Micro Hard Water container on white background

TriPart Micro soft water and TriPart Micro hard water side by side

The complete TriPart range: Grow, Bloom, Micro soft water and Micro hard water

Nutrient availability according to pH level

TriPart Micro Hard Water Fertiliser

$15.00

Capacity	Price	Price per L	vs 500 ml
500 ml	$15.00	$30.00	—
1 L	$23.00	$23.00	−23 %
5 L	$86.00	$17.20	−43 %
10 L	$150.00	$15.00	−50 %
60 L	$805.00	$13.42	−55 %

$5.00 × 3 with no fees Klarna.

This liquid mineral fertiliser, with an NPK formula of 5-0-1, is the part of the TriPart system that provides iron and trace elements, from seedling to harvest. Its hard water version contains less calcium nitrate, between 5 and 10%, for tap water exceeding 70 mg of calcium per litre.

Ref. TA-TPMHW-500·Hydroponic fertiliser

Capacity : 500 ml

500 ml

Customer support 7 days a week by email

Delivery within 2 to 15 business days

100 % secure payment

The summary

What it is: the part of the TriPart system that supplies iron and trace elements. NPK 5-0-1, in the hard water version.
Hard or soft water: choose this version if your tap water exceeds 70 mg of calcium per litre. This applies to many areas of the French water network.
What it contains less of: two to three times less calcium nitrate than the soft water version, because your tap water already provides it.
How much to use: 1.2 ml per litre during growth, 2 at pre-flowering, 1.6 at flowering. The calculator converts for your reservoir.
Caution: concentrate classified danger, H318, causes serious eye damage. Wear goggles and gloves when dosing.
Sizes and dispatch: 500 ml, 1 L, 5 L, 10 L, or 60 L, dispatched from France.

Iron and trace elements, version for hard tap water

TriPart Micro Hard Water is the part of the TriPart system that supplies iron and trace elements, in an NPK 5-0-1 formula. It is the former FloraMicro Hard Water, designed for hard tap water, which is common across many French water supplies. It contains two to three times less calcium nitrate than the soft water version, between 5 and 10%, because your water already supplies it.

🚰 Use in hard water

The bicarbonates in hard water neutralise the acid you add by releasing carbon dioxide, then the pH rises again as that gas escapes from the stirred solution, so a value set at 6.0 can drift back up to around 6.8 a few hours later. A pH-down corrector neutralises this reserve once and for all. Calcium, meanwhile, builds up as a white crust inside drippers and on probes, where it skews readings before eventually blocking flow. Blending mains water with rainwater in equal parts halves the bicarbonate level and the calcium hardness in one go.

Goggles and gloves when dosing

The concentrate carries a danger warning, the only one of the three containers to do so, with hazard statement H318, which flags the risk of serious eye damage. Wear goggles and gloves when measuring it out, and pour it over the reservoir rather than at face height. If it splashes into your eyes, rinse thoroughly and seek medical advice. Once diluted in the reservoir at the recommended doses, it no longer presents this risk.

🪨 The calcium in your water

The choice between the two versions depends on your water, and it should be settled before you place your first order. Hard water used with the soft-water version receives calcium it already contains, which unbalances the ratio with magnesium and eventually hinders its absorption. The reverse, osmosis water used with this version, causes a calcium deficiency that conductivity readings will not flag. In both cases, the problem takes several weeks to become visible, which is why it is worth checking once and for all.

The supplier's analysis

It is published each year with the bill. Look for the calcium line, if it reads above 70 mg per litre, this is the version for you.

The hardness test

A drop-test aquarium kit is sufficient. One French degree equals approximately 4 mg of calcium per litre.

The telltale sign

Limescale in the kettle, deposits on taps, or a pH that rises on its own are all signs of hard water.

Below 70 mg, use the soft water version

Check the calcium content of your water before ordering: below 70 mg per litre, or with reverse osmosis water, the soft water version is the right choice. A total hardness test kit gives you an answer in minutes and will serve you throughout the year for monitoring your top-up water.

🔬 Iron and trace elements

In hard water as elsewhere, this bottle supplies iron, manganese, zinc, boron, copper and molybdenum, precisely the elements that Grow and Bloom do not provide. An iron-deficient solution will quickly cause young leaves to turn yellow between veins that remain green. It is therefore used at every stage, from 0.5 ml per litre at first roots to 2 ml at pre-flowering. Hard water drives pH upward: the iron in this bottle, chelated with EDDHA and DTPA, withstands this, but the other elements are less readily absorbed outside the target range.

📦 Sizes and storage

Once opened, this container keeps for 5 years, sealed, away from light and frost. The iron chelates it contains degrade in light: leave it in its original packaging rather than decanting it into a clear bottle. The size you choose should reflect your annual consumption; the Micro empties at roughly the same rate as the Grow, since its dose varies little once growth is under way. There is also no obligation to buy all three parts in the same size.

Technical specifications

The essentials

Formula: NPK 5-0-1Identical to the soft water version on the label. The calcium content is what sets them apart.
Version: Hard waterTo be chosen when calcium exceeds 70 mg per litre, which is the case on many French water supplies.
What it provides: Iron and trace elementsManganese, zinc, boron, copper and molybdenum, in addition to iron.
Growth dose: 1.2 ml per litreHydroponics and coco. Reaches 2 ml in pre-flowering, then 1.6 ml during flowering.

Formula and parameters

Calcium nitrate: 5 to 10%Two to three times less than the soft water version, which reaches 22.5%.
Ammonium nitrate: 6 to 12%Noticeably higher than the freshwater version, which tops out at 3%.
pH not to be exceeded: 6,8Top of the application table range. In hard water, this is the main watchpoint, even though EDDHA and DTPA chelated iron remain stable beyond this level.
Appearance: Dark brown liquid, odourlessThe colour comes from the iron chelates and helps you tell the containers apart.

Dosing safety

Classification: Danger, H318Causes serious eye damage. The only one of the three bottles in the system to carry a hazard statement.
Dosing equipment: Goggles and glovesSafety advice P280. In case of eye contact, rinse thoroughly and seek medical advice.
SVHC listed substance: Boric acidBoron is an essential trace element. Its form appears on the ECHA candidate list.
Storage: Upright, sealed, in a cool placeStore in a dry, well-ventilated place, away from foodstuffs and combustible materials.

To budget for separately

pH corrector: Liquid pH-In hard water, it neutralises the bicarbonates that cause the pH to rise overnight.
Goggles and gloves: Concentrate classified H318Required when measuring doses. The risk disappears once the product is diluted.

6 further specifications are available in the detailed view.

In the box

1 container of TriPart Micro hard water in the chosen size: 500 ml, 1 L, 5 L, 10 L or 60 L.

Formula 5-0-1 taken from the label. Nitrate content, H318 classification, SVHC mention for boric acid, pH of the concentrate, density and appearance: French safety data sheet, version 9 dated 25 July 2024. Threshold of 70 mg of calcium per litre: TriPart page on the Terra Aquatica website, accessed 7 October 2026.

Grow, Micro, Bloom: what each one does in the TriPart system

The three bottles are not interchangeable and none of them is used on its own. Micro is used at a sustained dose at every stage, and it is the only one available in two versions depending on your water.

In soil-free growing, nobody else supplies calcium and iron In soil, the growing medium provides some of it, and it is the Grow or the Bloom that carries the most weight depending on the season. The substrate determines which bottle you need to reorder first.

	Total nitrogen (%)	Phosphorus, P2O5 (%)	Potassium, K2O (%)	Supplies calcium and iron	Supplies magnesium	Available in soft water and hard water versions	First roots (ml/L)	Full growth (ml/L)	Pre-flowering (ml/L)	Flowering (ml/L)	Present at a high dose at every stage	Classified hazardous	Safety glasses required when measuring	Liquid colour	Previous name
TriPart GrowYour choice	3 %	1 %	6 %	No	Yes	No	0,5 ml/L	1,8 ml/L	2 ml/L	0,8 ml/L	No	No	No	Green	FloraGro
Recommended TriPart MicroYour choice	5 %	0 %	1 %	Yes	No	Yes	0,5 ml/L	1,2 ml/L	2 ml/L	1,6 ml/L	Yes	Yes	Yes	Dark brown	FloraMicro
TriPart BloomYour choice	0 %	5 %	4 %	No	Yes	No	0,5 ml/L	0,6 ml/L	1,5 ml/L	2,4 ml/L	No	No	No	Pink	FloraBloom

TriPart Grow

Formula declared on the label

Total nitrogen (%)3 %

Phosphorus, P2O5 (%)1 %

Potassium, K2O (%)6 %

Supplies calcium and ironNo

Supplies magnesiumYes

Available in soft water and hard water versionsNo

Hydroponic dosage, millilitres per litre

First roots (ml/L)0,5 ml/L

Full growth (ml/L)1,8 ml/L

Pre-flowering (ml/L)2 ml/L

Flowering (ml/L)0,8 ml/L

Use and safety

Present at a high dose at every stageNo

Classified hazardousNo

Safety glasses required when measuringNo

Liquid colourGreen

Previous nameFloraGro

TriPart MicroRecommended

Formula declared on the label

Total nitrogen (%)5 %

Phosphorus, P2O5 (%)0 %

Potassium, K2O (%)1 %

Supplies calcium and ironYes

Supplies magnesiumNo

Available in soft water and hard water versionsYes

Hydroponic dosage, millilitres per litre

First roots (ml/L)0,5 ml/L

Full growth (ml/L)1,2 ml/L

Pre-flowering (ml/L)2 ml/L

Flowering (ml/L)1,6 ml/L

Use and safety

Present at a high dose at every stageYes

Classified hazardousYes

Safety glasses required when measuringYes

Liquid colourDark brown

Previous nameFloraMicro

TriPart Bloom

Formula declared on the label

Total nitrogen (%)0 %

Phosphorus, P2O5 (%)5 %

Potassium, K2O (%)4 %

Supplies calcium and ironNo

Supplies magnesiumYes

Available in soft water and hard water versionsNo

Hydroponic dosage, millilitres per litre

First roots (ml/L)0,5 ml/L

Full growth (ml/L)0,6 ml/L

Pre-flowering (ml/L)1,5 ml/L

Flowering (ml/L)2,4 ml/L

Use and safety

Present at a high dose at every stageNo

Classified hazardousNo

Safety glasses required when measuringNo

Liquid colourPink

Previous nameFloraBloom

Formulas recorded from the labels on the containers; classifications from the French safety data sheets. Dosages taken from the 2025 application chart, hydroponics and coco coir column. Values recorded on 10 September 2026.

Documents & manuals

TriPart application chart, hydroponics, coco and soil, multilingual document

The official stage-by-stage chart, in millilitres per litre for Grow, Micro, and Bloom, with the target conductivity and pH ranges. A multilingual document, with French and English presented side by side.

PDF · 4

Download

Safety data sheet TriPart Micro Hard Water, in French

Version 9 dated 25 July 2024. H318 classification, declared composition, protective equipment and first aid in the event of eye contact.

PDF · 4

Download

Safety data sheet TriPart Micro Hard Water, in English

Safety data sheet, version 9 dated 25 July 2024. Same content as the French version: H318 classification, declared composition, protection and first aid. Document in English.

PDF · 4

Download

Estimate your
delivery time

Not classified as hazardous for transport despite its H318 statement, which relates to handling rather than shipping. Tracked parcel from France. Weight ranges from approximately 600 grams for the 500 ml to approximately 12.5 kilos for the 10 L: exact shipping costs are shown at checkout once your address has been entered.

Frequently asked questions

6 questions

6 key questions

How do you know if your water exceeds 70 mg of calcium per litre?

Above this threshold, this is the version you need – and that applies to many French water networks.

Look up your water supplier's annual quality report, often included with your bill: find the calcium line in mg/L.
Alternatively, a drop-based aquarium hardness test kit will do: 1 French degree equals roughly 4 mg of calcium per litre, so 70 mg/L corresponds to around 17 French degrees.
Without any test kit, measure the conductivity of your tap water alone: above 0.4 mS before adding anything, you are in hard water territory.

A white residue in the kettle is a clue, not a measurement. And no, reverse-osmosis water is not required for success: hard water already supplies calcium and magnesium, and simply needs its pH correcting. An RO unit only becomes necessary with very heavily mineralised water – above 0.7 mS on its own – where there is no longer enough headroom for fertiliser beneath your target conductivity.

What is the exact difference from the freshwater version?

Just one difference, but it's a significant one: the calcium content.

	Hard water	Soft water
Calcium nitrate	5 to 10%	15 to 22.5%
Ammonium nitrate	6 to 12%	1.5 to 3%
Label formula	5-0-1	5-0-1
Concentrate pH	5.6	5.8

The iron, trace elements and usage rates are identical. If your water is soft, use the soft water version. If mistakenly used with hard water, it adds calcium to water that already contains plenty: conductivity rises faster than expected without any improvement in nutrition, and the excess calcium inhibits the uptake of potassium and iron. Nothing irreversible — the bottle remains usable by diluting it further or cutting your water with rainwater. For the same reason, a calcium-magnesium supplement is almost always unnecessary here, and often counterproductive.

How much Micro Hard Water for 10 litres, and how many litres per container?

12 mlin growth

20 mlin pre-flowering

10 mlin soil

Remember to subtract the starting conductivity of your water, which is not zero in hard water areas. At the growth-stage dose, expect approximately 830 litres of solution per litre of concentrate — 415 L from the 500 ml bottle — with the 5, 10, and 60 L formats following the same rule. Over a cycle run from seedling to harvest, consumption remains steady from start to finish. Used alone, it does not constitute a complete nutrient solution: it supplies iron and trace elements, but neither phosphorus nor potassium in any meaningful quantity.

Does the dosage change depending on the grow medium — hydro, coco or soil?

Values are in millilitres per litre, for Micro alone.

Stage	Hydro and coco	Soil	Target pH
First roots	0,5	0,2	5,5 to 6,5
First true leaves	1	0,6	5,5 to 6,5
Growth	1,2	1	5,5 to 6,5
Pre-flowering	2	1,5	6,4 to 6,8
Flowering	1,6	1,4	6,4 to 6,8

In hard water, keeping pH at the top of the range requires more attention than usual: above 6,8, the solution moves outside the range where most elements remain available for uptake. In soil, the hard water version is in fact recommended regardless of your water type, since the growing medium already supplies calcium.

My pH keeps rising on its own and my equipment is scaling up — what should I do?

This is the hallmark of hard water. Bicarbonates buffer the solution: until they are neutralised, the pH climbs again a few hours after each correction.

The solution is to neutralise them once and for all: add the pH-down in small amounts, allowing 20 minutes of circulation between each addition, until the value holds steady. It will then hold for several days. The iron in this bottle, chelated with EDDHA and DTPA, is stable at high pH; it is the uptake of other elements that deteriorates when hard water pushes the pH above the target range, even when the dose is correct.

For scale-encrusted equipment, carry out the following between crops:

Remove small components: drippers, diffusers, the pump impeller, and probes.
Soak them for 1 to 2 hours in white vinegar diluted by half.
Rinse thoroughly with clean water before reassembling.

Never pour this vinegar into a reservoir that is in use. Descaling must be done out of circuit, with components removed.

Can an aquaponic system use this Micro?

On a fishless system or a decoupled loop, yes, just as in hydroponics.

On a stocked pond, this bottle has the advantage of supplying the iron that is almost always lacking, but the drawback of also adding a significant amount of nitrates, which such a system already produces. For iron alone, a DTPA chelated iron is more precise; for overall nutrition, Aquaponic Mix is formulated specifically for this use.

How much TriPart Micro for your reservoir

Enter the volume of water in your reservoir. The calculation applies the full-growth dose for hydroponics and coco fibre, 1.2 ml per litre.

Reservoir water volume

5 L1000 L

0ml

of TriPart Micro hard water, full growth dose in hydroponics and on coco fibre

Pre-flowering dose, the maximum of the cycle

0 ml

Doses by growth stage in hydroponics and on coco fibre: 0.5 ml per litre at first roots, 1 at first leaves, 1.2 during growth, 2 at pre-flowering, 1.6 during flowering. In soil: 0.2, 0.6, 1, 1.5, and 1.4. Hard water adds its own background conductivity, often 0.4 to 0.5 mS when empty: measure it before adding anything and subtract it from your target.

Let us talk about your project

A question about this product or your setup? Our team will answer and advise you.

Email us Contact form

Interest-free instalment payments

Offered depending on the cart amount, at checkout.

Delivery in 2 to 15 working days

Depending on the products and shipping sites. Estimate by destination in the estimator on this page.

After-sales service 7 days a week by email or chat

Our team answers all your questions.

Shop responsibly

Become part of the change.

TriPart Micro Hard Water Fertiliser

The summary