The classic Oase Biotec 5.1 returns as the highly upgraded Oase BioSmart 18000 Pond Filter. Designed as the ideal entry-level flow-through filter, this system effectively removes pond debris and breaks down toxic chemicals, keeping your aquatic ecosystem thriving. Its clever internal design supports a high flow-through rate (up to 5,500 lph) while maximising oxygen enrichment. For the ultimate clear-water setup, the BioSmart 18000 pairs seamlessly with Oase Vitronic or Bitron C Ultraviolet Clarifiers (UVCs).

Advanced Filtration & Monitoring with the BioSmart

• Specialised Filter Foams: Featuring a targeted combination of blue, red, and green foams, the filter provides a massive surface area. This area ensures optimal biological development, enabling beneficial bacteria to efficiently break down harmful ammonia and nitrites.
• At-a-Glance Diagnostics: Taking the guesswork out of pond care, a built-in pollutant level indicator lets you know exactly when maintenance is required, while the integrated thermometer helps you track water temperatures during seasonal shifts.

Effortless Placement & Maintenance

• Hassle-Free Cleaning: Routine maintenance is incredibly convenient. Simply pump the easy-cleaning handles to compress the sponges, then pull the integrated slide valve on the sludge drain to flush the waste away, all without getting your hands dirty.
• Landscape Friendly: Because the unit can be buried up to one-third of its height, it is much easier to conceal this flow-through filter behind garden foliage or rockwork.

What accessories or tools are needed for installation, and is professional help recommended?

For help with installation and maintenance, read the product manual and explore our guide on installing pond filters.

Is this filter compatible with all pond pumps, or are there specific pump requirements?

As long as the pump you select accepts 25, 32 or 38mm flexible hose and is less than the maximum flow rate of 5500 lph then it would be compatible.

Helpful Guides:

The Beginner’s Guide to Choosing, Installing, and Maintaining Your Pond

How to Install a Pond Filter

The Best Pond Filters and Why You Need One for Your Pond

• Operating Instructions For Oase BioSmart 18000-36000 Pond Filter

Cut Off Time
Order by 2pm Monday to Friday for same day dispatch (Excluding Bank Holidays).

Direct/Palletised Delivery items may take longer.

Orders Under £49
Standard Delivery (2-3 working days) - £3.99
Express Delivery (1-2 working days) - £5.99

Orders Over £49
Standard Delivery (2-3 working days) - FREE!
Express Delivery (1-2 working days) - £2.99

Timeframes are for standard mainland UK addresses only excluding NI, Scottish Highlands & Islands.

Palletised Deliveries
Some large oversize products, typically items weighing more than 30kg, may require delivery via pallet and as such will arrive as a kerbside delivery only. The drivers in these instances are unfortunately not permitted to assist with the pallet beyond the drop off, and cannot aid in bringing packages into the property.

Pond Planet will contact you to book in delivery on a suitable working day. Delivery will generally take place between 9am and 5pm. To ensure there are no delays with delivery, please include a contact number when placing the order.

Pond Plant Deliveries & Surcharge
Pond plants are subject to a £5.99 delivery surcharge. Pond plants are sent directly from our supplier to make sure the plants you receive are fresh and in great condition. There is no limit on how many you can order for a single delivery charge. This charge is in addition to any other carriage costs for items sent directly from Pond Planet. Please allow 5 -10 working days for delivery.

Returns
If for any reason you are not satisfied with your purchase from Pond Planet, you may return the product(s) to us within 14 days of the purchase date for a refund or exchange.

Goods must be returned in perfect and unused condition, in their original packaging. The buyer must ensure that the goods are securely and adequately packed to avoid damage and the purchaser pays all postage costs. We recommend that products are returned by recorded delivery or by a carrier that requires a signature. Pond Planet accepts no responsibility for goods returned to us unless signed proof can be provided.