Charles Austen LD ACO22 Series
Charles Austen ACO22 and LD Compact Air Pumps
Small diaphragm pumps for aquariums, propagation systems and light aeration duties
The ACO22 range covers the compact end of Charles Austen aeration. Current models start with the ACO2201 at 1.3 litres per minute and extend through the ACO2202, 2203, 2204 and 2206 to the ACO2208 at 30 litres per minute.
That wide spread is important. The smallest models are aquarium and propagation pumps, not miniature versions of a large pond blower. At the other end, the ACO2208 has enough output for several modest outlets, but it still needs to be checked against depth and diffuser resistance.
This page is most useful when the job is small and you want a compact, economical diaphragm pump rather than an industrial aeration unit.
Compare Charles Austen ACO22 piston-pump models
The ACO2201, ACO2204 and ACO2208 show how output and application change through this linear-piston family. Check the individual duty and connection before replacing an older pump.
A quick guide to the model range
ACO2201, 2202, 2203 and 2204 provide approximately 1.3, 1.6, 2 and 4 l/min and suit light single-aquarium or small reservoir duties. The ACO2206 steps up to 10 l/min for multi-outlet aquariums and propagation systems. The ACO2208 reaches 30 l/min and is the model to consider for several air stones or a more substantial reservoir.
Published pressure also rises through the range, from 0.12 bar on the smallest model to 0.25 bar on the ACO2208. Do not compare flow in isolation.
Aquarium pump or pond pump?
The smaller ACO22 models are best treated as aquarium, hydroponic and indoor system pumps. Outdoor pond aeration introduces water depth, weather exposure and longer airline runs. If the intended diffuser is deep or the pond depends on aeration, a purpose-sized pond air pump is usually the safer choice.
The ACO2208 can serve light pond duties in the right installation, but it should not be bought simply because 30 l/min sounds generous. Check the performance at the required pressure.
Airline and placement
Use airline appropriate to the outlet and flow. Very narrow tube on the larger model wastes output, while an oversized maze of fittings makes a small system needlessly awkward. Keep the pump dry, ventilated and away from the edge of the water.
For several outlets, use a small manifold and match diffuser sizes. One large, deep diffuser can dominate the system and leave shallower branches uneven.
Our practical view
Choose the smallest pump that comfortably performs the real job, not the cheapest pump that produces some bubbles. A compact pump is excellent when used in its proper range; it becomes noisy and disappointing when asked to do the work of a pond aerator.
Useful Related Categories
If you are planning the complete installation, these sections are usually the most useful next step: Aquarium accessories · All pond air pumps · Air manifolds · Air stones and diffusers.
Frequently Asked Questions
What is the smallest ACO22 air pump?
The ACO2201 is the smallest current model on this page, listed at 1.3 l/min and 0.12 bar.
Which model provides the most air?
The ACO2208 is the largest current model here, listed at 30 l/min and 0.25 bar.
Are these pumps for aquariums?
The smaller models are particularly suited to aquariums, propagation tanks and compact reservoirs. Check the individual product duty before using one outdoors.
Can an ACO2208 aerate a pond?
It may suit a light, correctly designed pond-aeration duty, but depth, diffuser resistance and weatherproof installation must be considered.
Can I run several air stones?
The ACO2206 and ACO2208 can serve multiple modest outlets where output is sufficient and a manifold balances the branches.
Does the pump go in the water?
No. These are air pumps and must be kept dry. Only the airline and suitable diffusers belong in the water.
Do I need a non-return valve?
Use suitable backflow protection where required, especially if the pump cannot be positioned above the water level.
Why does my pump sound louder after fitting a diffuser?
The diffuser or airline may be too restrictive or partially blocked, causing higher back pressure.
Can I use one pump for two aquariums?
Yes, if the flow is adequate and each branch has appropriate adjustment and backflow protection.
Which airline size should I use?
Match it to the pump outlet and intended flow. Avoid long runs of unnecessarily narrow tube on the higher-output models.
Are the outputs adjustable?
Use a suitable bleed or manifold arrangement if adjustment is required. Do not heavily throttle the pump without checking the instructions.
Can these pumps run a sponge filter?
The smaller models can suit sponge filters where their output matches the filter and aquarium depth.
Are they suitable for hydroponics?
Yes, several models are appropriate for nutrient reservoirs and propagation systems, subject to the required airflow and installation conditions.
How do I choose between ACO2204 and ACO2206?
The ACO2204 is listed at 4 l/min and the ACO2206 at 10 l/min. Count the outlets and allow for depth and diffuser restriction.
Can you help me pick a model?
Yes. Tell us the water depth, number of outlets and application and we will help narrow the range.
