50 L bag of organic compost, three-quarters full, labelled peat-free

Bag of organic compost seen from the front, multilingual labelling

50 L bag of peat-free Terra Aquatica Light-Mix lightweight potting mix, standing upright, front view

Reverse of the bag: composition, analysis and certifications

Lightweight peat-free compost for seedlings and pot growing, 50 L

Name: Lightweight peat-free compost for seedlings and pot growing, 50 L
Brand: Terra Aquatica
SKU: TA-SUB-LM-50
Price: 16.9 EUR
Availability: InStock

16,90 €

5,63 € × 3 with no fees Klarna.

Light Mix is a 50 L organic compost made from composted pine bark, coir, wood fibre and perlite. Its fertilisation is deliberately light, at 2 kg of organic NPK 6-3-4 fertiliser per cubic metre.

This way you stay in control of nutrition from day one, instead of depending for several weeks on the compost's own reserves. It can be used in organic farming.

Ref. TA-SUB-LM-50·Growing medium

Customer support 7 days a week by email

Delivery within 2 to 15 business days

100 % secure payment

The summary

What it is: a 50 L peat-free organic compost, made from composted pine bark, coir, wood fibre and perlite.
Lightly fertilised: it contains 2 kg of NPK 6-3-4 organic fertiliser per cubic metre, which leaves you in control of feeding.
Its three values: the pH is 6, the conductivity 30 mS/m and the water retention 450 ml per litre of grow medium.
What it is for: it suits seedlings, cuttings, pot growing and soil improvement in borders.
Organic farming: this compost can be used in certified production.
Size: the bag holds 50 L and weighs 15.6 kg.

Organic compost 50 L, lightly fertilised, pH 6, for seedlings, cuttings and pots

Light Mix is a growing compost designed so that you decide on the nutrition. Its fertilisation, 2 kg of NPK 6-3-4 organic fertiliser per cubic metre, is deliberately light, whereas a universal compost carries the plant for 6 to 8 weeks on its own reserve. With this one, nutrition starts with your first feed, which is what makes it a medium for seedlings and controlled growing.

🧱 What the bag contains

Composted pine bark

It provides structure, with particles that do not compact and let air circulate for months.

Coconut fiber

It provides water retention and makes up the 450 ml per litre of the mix.

Wood fibre

It lightens the mix and helps aerate it, along with the bark and perlite.

Perlite

It is an expanded volcanic rock, incompressible. It keeps air in the mix even when wet and packed down.

🌱 A growing medium you control

With a rich compost, you lose some control over nutrition. Its reserve is released at its own pace, unrelated to the plant's stage, and it adds to what you supply. With a lightly fertilised medium, what the plant receives is what you have poured in, and you adjust the formula between growth and flowering. Three values describe this compost: a pH of 6, the range where most elements remain available, a very low conductivity of 30 mS/m, and a water retention of 450 ml per litre, or roughly 22 litres of water held per bag.

The low salt content is exactly what a young root needs, as a rich compost would burn it, which is why this mix is used first and foremost for seedlings and cuttings. It is then suitable for potted growing with a complete fertiliser, and for improving a flower bed when mixed with the existing soil. At the end of the crop, it goes on the compost heap or into the vegetable patch. Our article on the indoor seedling area covers this stage in detail.

Fertiliser from the very first watering

Plan on an all-in-one fertiliser at the same time, since feeding starts with the very first watering. The nutrient content of this compost is deliberately low, so it is your fertiliser that carries the plant and you adjust its formula between growth and flowering. A pH test usefully completes the set, as the pH of the watering water determines what the plant can actually absorb.

It does not go in a water circuit

This potting compost is made for a watered pot, not for a system where the water circulates. For a continuous irrigation pot or an ebb and flow table, turn to clay pebbles or coco fibre, which hold up in a circuit. An organic compost placed in a film of water releases its fine particles, clouds the solution and ends up in the pump, while losing the structure that makes it worthwhile.

🍄 A living mix

This compost is rich in beneficial micro-organisms, bacteria and fungi that colonise the root zone. They contribute to the slow decomposition of the organic fraction, and therefore to the gradual release of the organic fertiliser in the mix. They thrive in a moist, airy grow medium at ordinary temperatures, which are the conditions of an indoor seedling. Two things destroy them: sterilising the compost in the oven or microwave, and a systemic fungicide treatment, which does not distinguish between fungi. If you raise your seedlings with this mix, avoid sterilising it and keep treatments for proven cases.

📦 The 50-litre bag

The 50 L of the bag fill around fifty one-litre pots, or about ten 5-litre pots, which comfortably covers a seedling season for a home gardener. The bag can be resealed and kept from one year to the next provided it stays dry and frost-free, as the structure of the mix does not break down but the organic fraction slowly becomes depleted. Compost left for 2 years in a damp shed settles and loses some of its water retention, which can be remedied by mixing in a handful of perlite before use.

Technical specifications

The essentials

Volume: 50 LThe bag weighs 15.6 kg dry, and a good deal more once the grow medium is wet.
Composition: Bark, coir, wood, perliteComposted pine bark, coconut fibre, wood fibre and perlite, in a ready-to-pour mix.
Pre-fertilisation: 2 kg/m³, NPK 6-3-4Organic fertiliser, at a light feed: provide nutrients from the very first watering.
pH: 6This is the zone where most nutrients remain available to the plant.
Conductivity: 30 mS/mA low value, which suits young roots and confirms the low fertiliser load.
Water retention: 450 ml/LA 50 L bag therefore holds about 22 litres of water.

To budget for separately

Fertilizer: A complete fertiliserFeeding starts with the very first watering and continues throughout the cycle.
Containers: Seedling pots or traysWork out the volume before ordering: 50 L fills about fifteen 3 L pots.

In the box

1 bag of Light Mix potting compost of 50 L, weighing 15.6 kg dry.

Volume, pH, conductivity, water retention, pre-fertilisation and the organic farming mention taken from the bag, composition and weight from the manufacturer's shop, on 08/10/2026. The fifteen or so 3 L pots is an order of magnitude calculated from the volume of the bag.

Light potting compost or coco fibre?

Two growing media, for two ways of managing nutrition.

A compost-based mix or a neutral medium If the water circulates or flows back up in your setup, go for coir without hesitation: the organic particles in a potting compost break down and end up in the pump. The questionnaire will help you decide in all other cases.

	Already includes everything you need to get started	You decide on all the inputs	Tolerates a missed fertiliser dose	Seedlings and cuttings	Pot cultivation	Circulating system	Flood table	Volume (L)	Weight (kg)	Reusable over several cycles
Recommended Lightweight peat-free compost for seedlings and pot growing, 50 LYour choice	Yes	No	Yes	Yes	Yes	No	No	50 L	15.6 kg	No
50 L coco fibre, natural or with perliteYour choice	No	Yes	No	Yes	Yes	Yes	Yes	50 L	12.5 kg	Yes

Lightweight peat-free compost for seedlings and pot growing, 50 LRecommended

Nutrition

Already includes everything you need to get startedYes

You decide on all the inputsNo

Tolerates a missed fertiliser doseYes

Use

Seedlings and cuttingsYes

Pot cultivationYes

Circulating systemNo

Flood tableNo

The bag

Volume (L)50 L

Weight (kg)15.6 kg

Reusable over several cyclesNo

50 L coco fibre, natural or with perlite

Nutrition

Already includes everything you need to get startedNo

You decide on all the inputsYes

Tolerates a missed fertiliser doseNo

Use

Seedlings and cuttingsYes

Pot cultivationYes

Circulating systemYes

Flood tableYes

The bag

Volume (L)50 L

Weight (kg)12.5 kg

Reusable over several cyclesYes

Composition, weight and uses taken from the bags and the manufacturer's shop, on 08/10/2026. The two bags complement each other: a crop can start in light compost and carry on in coir.

Documents & manuals

Safety data sheet, Organic Soil Light Mix

Manufacturer's regulatory document, in English.

PDF

Download

Manufacturer's page, Organic Soil Light Mix

Composition, pH and conductivity values, recommended uses, in English.

LIEN

Download

Estimate your
delivery time

50 L bag weighing 14 kg. Volume counts for more than weight when calculating shipping: a bag of compost takes up the space of several standard parcels. Exact costs and final delivery times are shown at checkout once your address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient. Lead times run from the date of dispatch, excluding public holidays.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

Should you add fertiliser straight away?

Can it be used in hydroponics?

How many pots does a 50 L bag fill?

Can this potting compost be used in organic farming?

How much does a bag weigh once watered?

What should I do with the potting compost after a crop?

White mould is appearing on the surface, is it serious?

No. On a damp organic grow medium, a white felty film on the surface is an ordinary fungal growth, harmless to the plant and to you.

It points to two things: excess moisture at the surface, and poor air circulation. Space out your watering, ventilate the room, and scrape off the top layer if its appearance bothers you. This potting compost is, incidentally, rich in beneficial micro-organisms: not all the fungal life in a grow medium is a problem.

Light Mix potting compost or coir: which should you choose?

Point	Light Mix	Coco coir
Nature	blended compost	neutral grow medium
Pre-fertilised	yes, lightly	no
Pot growing	yes	yes
Hydroponics	no	yes

Light Mix is a gardener's compost, while coco coir is a soilless growing medium.

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.

Lightweight peat-free compost for seedlings and pot growing, 50 L

The summary