Cone, cylinder and pierced-plug grow sponges, with rooted basil and tomato plants

Cylindrical growing sponges, loose, pre-expanded

Hydroponic germination sponge pods in peat — main view of the pack for seedlings of lettuces, herbs and tomatoes

Loose drilled grow sponges, with young plants whose roots pass through the sponge

Dimensions of the three grow sponges once swollen: 6.2 cm cone, 3.7 cm split cylinder and 4 cm pierced plug

Set of 20 growing sponges for seedlings

Name: Set of 20 growing sponges for seedlings
Brand: Univers Aquaponie
SKU: EC-CONE-20
Price: 55.0 AED
Availability: InStock

Dhs. 55.00

Dhs. 18.33 × 3 with no fees Klarna.

These growing sponges, also called growth stones, swell in water and hold their shape. The seed sits in the sponge, and the sponge is transplanted whole with its roots. They come in three shapes, cone, cylinder or slotted plug, in packs of 20.

Ref. EC-CONE-20·Germination substrate

Format : Cone

Cone

Cylinder

Pre-drilled stopper

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Delivery within 2 to 15 business days

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The summary

What you receive: 20 growing sponges, in cone, cylinder or slotted plug shapes.
Which format: the cone for a capsule, the cylinder for a small pot, the plug for a tray.
Preparation: a few minutes in water, then one or two seeds in the hole or slit.
At transplanting: the sponge goes in whole with its roots, in a basket, a pot or in soil.

Growing stones in packs of 20, cone-shaped, cylindrical or with a pierced plug

A growing sponge, also called a growth stone, is a small, soft plug that swells in water and keeps its shape. You place the seed in it, the plug stays moist around the seed, and the roots grow through it until they emerge. You then move the young plant, sponge and all, to its next support without any unpotting: a grow basket, a small pot or the open ground.

📐 One shape per slot

Choose the shape according to the housing that will hold the sponge during germination, and not according to the species, since each one takes a lettuce seed as readily as a tomato seed. First soak your sponges for 3 to 5 minutes in water, until they are soft right through, then leave them to drain for a few minutes, because a dripping sponge deprives the seed of air. Then place one or two seeds at the bottom of the hole or in the slit, leaving very fine seeds on the surface.

Cone

Long and slim, 62 mm tall once swollen, with a small hole at its tip, it slides into the narrow capsule of an indoor garden right down to the water.

Cylinder

Short and squat, 30 mm at the top by 37 mm tall once expanded, slotted on top to grip the seed, it fits in a small pot or a 4.5 cm basket.

Pre-drilled stopper

The widest one, 35 mm at the base by 40 mm high, combines coco coir and peat. Its central hole holds the seed.

The sponge that dries out during germination

A sponge that dries out stops germination, and a seed that has already begun to germinate will not survive that drying out. Check the moisture by touch every day until the roots have emerged, keep your sponges under a clear lid and do not leave them in full sun behind a window.

A tray of 40 cells for germination

The set of 3 trays of 40 cells keeps your sponges warm and moist under a dome with adjustable ventilation, on a watertight base that allows bottom watering. Place a cylinder or a drilled stopper in each cell: this way you can raise up to 40 seedlings per tray, and the humidity under the dome limits how much the sponges dry out between checks. Open the dome's vent as soon as the first shoots appear.

🌊 In an aquaponic system

A growing sponge carries no soil. Transplanted into a net pot set on your aquaponic tank, it does not load the fish water with the fine particles that compost would bring, and your plant arrives in the system with its roots already showing. The cylinder fits into a 4.5 cm pot, the perforated plug into a 5 cm pot. The sponge stays around the roots until harvest, then goes to the compost heap with the plant.

📅 A batch of 20 seedlings

A pack of 20 sponges covers a complete series of spring seedlings for a small system, for example 12 lettuces for a gutter, 4 basil plants and 4 spare sponges for resowing where a seed has not germinated. If both of your seeds germinate in the same sponge, snip the weaker one off at the base rather than pulling it out, which leaves the roots of the one you keep intact. To harvest lettuces continuously, start a small batch every 2 to 3 weeks rather than all 20 sponges at once, and keep the rest of the pack dry in its sealed bag.

Technical specifications

The cone and the cylinder

Inflated cone: 10 to 20 × 62 mmTop and base, then height; 8 to 16 × 52 mm when dry
Inflated cylinder: 25 to 30 × 37 mmBase and top, then height; 20 to 25 × 30 mm when dry

The drilled stopper

Inflated: 25 to 35 × 40 mmTop and base, then height
Material: Coir and peatIt holds water without falling apart when transplanting

Use

Soaking: 3 to 5 minutesUntil the sponge is soft all the way through
Transplanting: Whole sponge, no need to remove it from the potAs soon as the roots come out through the bottom

To budget for separately

Lifting plate: Domed trayIt keeps the moisture around the sponges
Growing baskets: Net potsFor placing plants on a water circuit

In the box

20 growing sponges, in the size of your choice

Dimensions, material and soaking time: values stated for this model, recorded on 01/10/2026.

Which sponge for your seedlings?

Three sponge shapes for three housings: the capsule, the small cup, the tray.

Capsule, pot or tray The shape of the sponge follows the housing that receives it.

	Maximum diameter (mm)	Height (mm)	Shape	Fits into	Price
ConeYour choice	20 mm	62 mm	long cone, small hole at the top	indoor garden capsule	Dhs. 55.00
Recommended CylinderYour choice	30 mm	37 mm	short cylinder, split along the top	4.5 cm pot or basket	Dhs. 55.00
Pre-drilled stopperYour choice	35 mm	40 mm	wide plug, drilled right through	cell tray or 5 cm basket	Dhs. 55.00

Cone

The inflated shape

Maximum diameter (mm)20 mm

Height (mm)62 mm

The use

Shapelong cone, small hole at the top

Fits intoindoor garden capsule

The price

CylinderRecommended

The inflated shape

Maximum diameter (mm)30 mm

Height (mm)37 mm

The use

Shapeshort cylinder, split along the top

Fits into4.5 cm pot or basket

The price

Pre-drilled stopper

The inflated shape

Maximum diameter (mm)35 mm

Height (mm)40 mm

The use

Shapewide plug, drilled right through

Fits intocell tray or 5 cm basket

The price

Dimensions once inflated, taken from the product descriptions on 01/10/2026 and from the dimension diagram.

Estimate your
delivery time

The exact shipping cost is calculated at checkout, based on the total weight of your order and the destination. Lead times start from dispatch and remain estimates. For a destination not listed here, write to us at contact@univers-aquaponie.com.

Frequently asked questions

6 questions

6 key questions

Cone, cylinder or drilled plug: which should you choose?

Format	Expanded	Where it sprouts
Cone	10 to 20 × 62 mm	Indoor garden pod
Cylinder	25 to 30 × 37 mm	4.5 cm cup or basket
Drilled plug	25 to 35 × 40 mm	Cell tray or 5 cm basket

All three formats take one or two seeds and are transplanted whole.

How long should they be soaked?

How do you sow in a grow sponge?

Should the sponge be removed at transplanting?

Are these sponges suitable for an aquaponic tank?

What is the difference from peat pods?

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Set of 20 growing sponges for seedlings

The summary