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External Filters

External canister filters are ideal for large aquariums and for coping with large tropical fish or goldfish. External filters are able to hold large amounts of filter media and provide excellent biological and mechanical filtration. Charterhouse Aquatics stock all the biggest brands of external filter and external filter media for you to buy including Eheim, Oase, Tetra, Fluval and many many more.

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Shop External Aquarium Filters for Crystal-Clear Water

Keep your aquarium water clean, healthy, and stable with our range of high-performance external filters. At Charterhouse Aquatics, we stock a wide selection of trusted brands including Eheim, Oase, Fluval, and Tetra—ideal for freshwater, planted, and tropical aquariums of all sizes. External canister filters are a popular choice among hobbyists for their superior mechanical and biological filtration, quiet operation, and ease of maintenance. Whether you’re running a compact nano tank or a heavily stocked community setup, we have the right solution to suit your needs. From beginner-friendly filter kits to advanced models with electronic control and adjustable flow, our range covers every level of experience and tank type. Not sure which filter is right for your aquarium? Our expert team is here to help you find the best match for your tank size, livestock, and filtration goals. We also carry a full selection of replacement media, hoses, impellers, and other essential filter accessories to keep your system running at peak performance. Explore the full collection of external aquarium filters today and enjoy fast UK delivery and top-tier customer support with every order.
Shop External Aquarium Filters for Crystal-Clear Water

CHARTERHOUSE REWARDS

A little thank you, every time.

Earn points when you shop, then turn them into money off at checkout.

Points with every eligible purchase8 stamps. 10% off.

COLLECT POINTS

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Earn automatically on eligible product spend after discounts, excluding delivery.

SPEND POINTS

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Switch on your points at checkout to save on eligible products.

Normal value: 100 points = £1 off. Flash offers can increase this.

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How to earn and spend your points

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1. Shop and earn points

Earn 1 point for every £1 of eligible product spend after discounts, excluding delivery.

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2. Use your points at checkout

Sign in at checkout and switch on “Use my points”. Your available points become money off automatically—no voucher to claim. Savings cover eligible products only; any points you cannot use stay in your balance.

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3. Get more with flash offers

Watch for flash offers with double or triple points, or extra value when you spend them.

YOUR STAMP CARD

Eight stamps. One lovely thank you.

Each order with £250 or more in products after discounts, excluding delivery, earns one stamp. Fill all 8 slots to unlock a 10% off code, valid for 365 days. Use it alongside your points.

Sign in to see how close you are to your next reward.

Good to know

Why are some points pending?

Purchase points have an approval period before they become available. Your balance shows available points separately from pending points.

How long do my points last?

When points expiry applies, your balance stays valid for 365 days from qualifying rewards activity. Earning eligible rewards, redeeming points or a balance adjustment renews that window. Simply visiting the shop does not renew it.

Can I use points with my stamp reward?

Yes. Add your 10% stamp reward code at checkout and switch on your points. Your final saving depends on the eligible product total and any other discount restrictions.

What happens if I return something?

Earned points are adjusted for returns. Points used on refunded products are restored proportionally. If a refund takes a qualifying order below £250, its stamp is removed.

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