Growrilla cylindrical air stone in short format, fine grey grain and black fitting for the air pipe

Growrilla cylindrical airstone in long format, three-quarter lying view with its black nozzle

XL air stone of 105 x 30 mm, grey porous cylinder between two black square bases, with connector nozzle

Cylindrical air stones, 50 to 105 mm long

Name: Cylindrical air stones, 50 to 105 mm long
Brand: Growrilla
SKU: GROW-PACK-POR1002020B-10
Price: 22.9 EUR
Availability: InStock

22,90 €

These cylindrical air stones oxygenate the nutrient solution in RDWC, DWC, hydroponic and aquaponic systems. They come in 50 x 50 mm, 100 x 50 mm or 105 x 30 mm, and are sold in packs of 10, 25 or 50, with the 105 x 30 mm size in packs of 10. Their fine grain produces small bubbles that stir the solution around the roots.

Ref. GROW-PACK-POR1002020B-10·Hydroponic aeration accessory

Size : 50 × 50 mm ×10

50 × 50 mm ×10

100 × 50 mm ×10

50 × 50 mm ×25

50 × 50 mm ×50

100 × 50 mm ×25

100 × 50 mm ×50

105 × 30 mm ×10

Customer support 7 days a week by email

Delivery within 2 to 15 business days

100 % secure payment

The summary

What it is: the porous diffuser that turns the output of an air pump into a cloud of fine bubbles.
Three sizes: 50 x 50 mm for a 19 L tank, 100 x 50 mm for larger volumes, 105 x 30 mm to stand upright or lie flat.
What clogs it: the mineral salts that seal the pores, cycle after cycle.
How many you need: one per growing tank, two or three in a reservoir or a pond.

Replacement cylindrical diffusers in three sizes, in packs of 10, 25 or 50

The cylindrical air stones, made in Italy, are porous diffusers that turn the output of a pump into fine bubbles to oxygenate the nutrient solution in RDWC, DWC, hydroponics or aquaponics. They come in 50 x 50 mm, one cylinder per 19 L tank, in 100 x 50 mm for large volumes, with 2 to 3 pieces per reservoir, and in 105 x 30 mm.

A submerged root breathes, and what it breathes is the oxygen dissolved in the water, not the air above it. An air stone breaks the output of a pump into bubbles fine enough to remain in the water column for a long time, and it is during this slow rise that oxygen passes into solution. The circulation it creates also renews the water in contact with the roots.

Bubble size is what separates a good diffuser from a poor one. Large bubbles travel quickly through the tank, burst at the surface, and have given up almost nothing on the way, whereas a fine cloud fills the full depth of the water, lingers there, and stirs it. That is why you judge an airstone by watching it work, rather than by listening to the pump driving it.

🫧 Three diffuser formats

The first two sizes have the same 50 mm diameter and differ in length. The 50 x 50 mm cylinder is the one that equips each 19 L tank of an RDWC PRO system: one per tank, placed on the bottom, beneath the roots. The 100 x 50 mm size is intended for large volumes, such as a buffer tank, mixing tank or pond, where a short diffuser no longer covers the whole body of water. The XL size of 105 x 30 mm, longer and slimmer, rests on two square bases that hold it equally well upright or lying down, so its whole porous surface diffuses air, at the bottom of a DWC pot as in a tank.

A longer format offers more porous surface, and so it needs more air to produce a fine cloud along its whole length. On a pump already loaded by several outlets, replacing a short cylinder with a long one often has the opposite effect to the one intended: the bubbles get bigger, because the pressure is lacking. Count your outlets and check the flow rate of your pump before changing format.

Handling the stones without knocking them

An air stone is fragile, and a knock against the bottom of a tank, a fall onto a tiled floor or too much pressure when you push the air pipe onto it is enough to crack it. A cracked stone then lets air escape through the crack in a string of large bubbles, instead of diffusing it across its whole surface. Lower it to the bottom of the tank by hand rather than dropping it, and hold it by its nozzle when you slide the pipe on.

A multi-outlet pump for a network

Each tank needs its own air line, and the Hailea air pump comes in diaphragm models for one or two diffusers, and in piston models supplied with a 6-outlet manifold for an entire network. Feeding each air stone from its own outlet gives you a comparable flow in every tank, and lets you shut one off without touching the others. Choose the model based on the number of stones to supply and on the depth of water above them.

These diffusers are sold in packs of 10, 25 or 50 because they are replaced in step with your growing cycles. A solution with falling dissolved oxygen damages the roots long before the foliage shows it, so a clogged stone should be replaced without delay. Keep your spare stones dry and in their packaging, so that they reach the tank clean on the day you need them.

🧽 Pores that close back up

An air stone clogs up over time. The mineral salts in the solution gradually crystallise in its pores and close them, so the air only escapes through the passages that remain open, in larger and sparser bubbles. The process is slow and steady, and you can spot it by watching the bubbles each time you lift the lid for a reading. Four signs tell you where it stands and how to get it working again.

The sign

The dense cloud becomes a string of large bubbles, often on one side only.

The cause

The salts in the solution crystallise in the pores and block them up.

The bath

A soak in water with citric acid added will dissolve the deposit.

Brushing

A soft brush finishes the cleaning without enlarging the pores.

🌡️ Oxygen and heat

Water cannot hold more than a certain amount of dissolved oxygen, known as saturation, and this limit falls as the temperature rises: roughly 9.1 mg/L at 20 °C, 8.3 mg/L at 25 °C and 7.6 mg/L at 30 °C in fresh water. An air stone brings the solution closer to this limit, but it cannot push it beyond it. The roots, meanwhile, consume more oxygen as the water warms up, so a warm solution suffers from both constraints at once. Check your air stones before summer, and keep the solution at 24 °C at most.

🐟 In a fish pond

A diffuser dissolves oxygen into the water without affecting the pH or the nutrition, so it is used in the same way in pond water as in a nutrient solution. Fish, like the nitrifying bacteria in the filter, consume oxygen, and their needs increase with temperature just when the water holds the least of it. It is in summer, towards the end of the night, that your pond contains the least.

In a pond or an aquaponic rearing tank, spread two or three 100 x 50 mm cylinders throughout the volume rather than grouping them in one spot, and supply each from its own air outlet. This aerates the whole body of water, including the corners where it circulates little. Before the hot weather, read the guide on summer care for an aquaponic system, which details the other tasks of the season.

Technical specifications

The essentials

What it is: Cylindrical porous diffuserIt breaks the flow from an air pump into fine bubbles.
Formats: 50 x 50, 100 x 50 or 105 x 30 mmLength, then diameter. The 105 x 30 mm size has two square bases.
Quantities: 10, 25 or 50 piecesThe 105 x 30 mm size is sold in packs of 10.
Origin: Italy

Where it goes

19 L growing tank: 1 cylinder of 50 x 50 mm.Placed at the bottom, beneath the roots.
Tank or pond: 2 to 3 cylinders of 100 x 50 mmSpread throughout the volume rather than grouped together.

Maintenance

Handling: Shock-freeA cracked airstone lets air escape through the crack.
Cleaning: Citric acid bath, soft brush

To budget for separately

Air pump: 1 pump, one outlet per airstone
Air pipe: Flexible, one line per stone

2 further specifications are available in the detailed view.

In the box

10, 25 or 50 cylindrical diffusers in the chosen size, depending on the pack ordered.

Sizes and uses taken from the manufacturer's product pages on 07/10/2026, XL size on 08/10/2026. Oxygen saturation: USGS tables for freshwater at sea level.

Manufacturer and product safety

Manufacturer: Growrilla di Milone Giulio
Postal address: Via Fiano 207, 10070 Robassomero (TO), Italie
Contact: info@growrillahydroponics.com
Website: growrillahydroponics.com

Information provided under Regulation (EU) 2023/988 on general product safety.

Estimate your
delivery time

The parcel, light and compact, is dispatched from the workshop in Robassomero, near Turin. The diffusers are fragile under compression: they are shipped firmly secured, and a parcel that arrives dented should be flagged before opening. Exact shipping costs and final delivery times are displayed at checkout once your address has been entered. Outside the European Union, import duties and taxes remain the responsibility of the recipient.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

Is one per pot enough?

How do you know when an airstone is clogged?

Can an airstone be cleaned rather than replaced?

What is the difference between the sizes?

Can you fit a large format into a 19 L tank?

Should they be connected in series or in parallel?

Are they suitable for a fish pond?

Why does oxygen run low in summer?

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.

Cylindrical air stones, 50 to 105 mm long

The summary