Aquarium Accessories

Aquarium Accessories and Internal Filters

Compact filtration and circulation equipment chosen for real aquarium duties

This section currently centres on Charles Austen internal aquarium filters rather than an indiscriminate list of ornaments and gadgets. The two ranges do slightly different jobs: HL-BT filters offer fixed model outputs with useful head capability, while the MV range provides compact adjustable circulation for smaller aquariums and reservoirs.

An internal filter is convenient because the pump and filter body sit inside the aquarium, but the correct size still depends on livestock, feeding, aquarium volume and how easily the unit can be maintained. A quoted litres-per-hour figure is measured under favourable conditions and will fall as media accumulates waste.

We would rather help you choose a filter that can be cleaned easily and run with spare capacity than sell a tiny unit that looks neat but struggles after a week of normal feeding.

Products in the Current Aquarium Accessories Range

The Aquarium Accessories products on this page link directly to their current specifications, variations and prices. If the right option is unclear, tell us what you already own and what you need the new item to do.

HL-BT or MV?

The HL-BT series spans 200 to 1,000 l/h and adds a published maximum head figure, making it useful where the outlet has to lift or direct water. The MV series is a compact adjustable range for small aquariums, desktop water features and modest reservoir circulation.

Neither range should be selected from aquarium litres alone. Consider the fish load, food input, media volume and how much flow the inhabitants will tolerate.

What an internal filter can and cannot do

Internal filters provide mechanical capture and a surface for biological bacteria, while the moving outlet improves circulation and gas exchange. They are practical for smaller aquariums, quarantine tanks and installations where an external canister would be excessive.

They still need maintenance. Rinsing clogged media in untreated tap water can damage the biological colony; use removed aquarium water where appropriate and never clean every mature biological component aggressively at the same time.

Place the outlet for useful circulation

Aim the return so the surface moves gently and debris is encouraged towards the intake. Avoid blasting slow-swimming fish or creating a dead corner behind decoration. If extra oxygen is required, combine circulation with suitable aeration rather than assuming a submerged outlet adds enough oxygen by itself.

Always isolate electrical equipment before putting your hands in the aquarium and follow the current product instructions for submersion, cable routing and cleaning.

Advice from a small specialist retailer

The best filter is the one that suits the fish and is easy enough to clean regularly. Tell us the aquarium size, livestock and whether you want gentle filtration or stronger circulation. We can help you choose between the compact MV and more capable HL-BT ranges.

Useful Related Categories

If you are planning the complete installation, these sections are usually the most useful next step: HL-BT internal filters · MV internal filters · Air pumps · Air stones and diffusers.

Frequently Asked Questions

What products are in this aquarium accessories category?

The current range focuses on Charles Austen HL-BT and MV internal aquarium filters for filtration and circulation.

What is an internal aquarium filter?

It is a combined pump and filter body that operates inside the tank, providing water movement and media for mechanical and biological filtration.

How do I choose the correct flow?

Consider aquarium volume, livestock, feeding, desired turnover and the amount of flow the fish can comfortably tolerate.

Does the advertised flow stay the same?

No. Media, lift, fittings and accumulated debris reduce real flow, which is why sensible spare capacity and cleaning access matter.

Are internal filters suitable for goldfish?

They can be, but goldfish produce substantial waste. Choose generous filtration and maintain it frequently.

Can I use one in a shrimp tank?

Potentially, but the intake may need suitable protection and the flow must be gentle enough for the inhabitants.

Does an internal filter add oxygen?

Surface movement improves gas exchange, but heavily stocked or warm systems may still benefit from a separate air pump and diffuser.

How often should I clean the media?

Clean it when flow falls or debris accumulates, without stripping all biological media at once. Frequency depends on stocking and feeding.

Can I wash filter media under the tap?

For mature biological media, rinsing gently in removed aquarium water is normally safer than chlorinated tap water.

Where should the filter sit?

Position it so the intake can collect debris and the outlet creates broad circulation without stressing the fish.

Can these filters run in a small water feature?

Some models can provide compact circulation, but confirm water depth, access and the exact installation requirements.

What is the difference between HL-BT and MV?

HL-BT covers fixed model outputs up to 1,000 l/h with published head figures; MV is a smaller adjustable range for modest duties.

Should I switch the filter off at night?

No. Biological filtration and circulation are normally intended to run continuously.

Can an internal filter replace water changes?

No. Filtration does not remove every dissolved waste product; routine testing and water changes remain important.

Can you help me choose?

Yes. Send us the tank volume, fish species and approximate stock level and we will point you towards the most appropriate range.