New Arrivals: I-Series Internal Aquarium Filters

We've just added four new internal aquarium filters to the range: the I-300, I-500, I-1000 and I-1500. These are compact, submersible filters designed to sit inside freshwater or marine tanks, combining mechanical filtration with a strong oxygenation effect to help keep water clear and support fish health. Each model in the I-Series offers a different flow rate, so whether you're running a small nano tank or a larger community setup, there's an option sized to suit. All four feature adjustable flow control, letting you fine-tune output to match the needs of your fish and plants, from calmer community tanks to more active setups. When choosing between them, match the filter's flow rate to your tank volume and stocking level — as a general guide, aiming for a flow rate that turns over your tank volume several times per hour is a sensible starting point, and it's worth checking our filter sizing guidance before you buy.

Internal Aquarium Filter 370L/H I-300

The smallest of the new arrivals, the I-300 delivers a flow rate of 370 litres per hour from a compact 162 x 50 x 52mm footprint, powered by a 3W motor. It's a good fit for smaller tanks where space is limited but you still want reliable circulation and mechanical and biological filtration.
View the I-300 Internal Aquarium Filter

Internal Aquarium Filter 500L/H I-500

The I-500 steps up to a 500 litres per hour flow rate, measuring 197 x 58 x 64mm and running on a 6W motor. Its adjustable flow control makes it suitable for a range of tank types when setting up a new freshwater tank or upgrading existing filtration.
View the I-500 Internal Aquarium Filter

Internal Aquarium Filter 1000L/H I-1000

The I-1000 offers a 1000 litres per hour flow rate with a 228 x 65 x 72mm body and a 15W motor, suited to larger tanks or more heavily stocked setups, including marine aquarium setups.
View the I-1000 Internal Aquarium Filter

Internal Aquarium Filter 1500L/H I-1500

The I-1500 is the highest-capacity model in the new range, with a flow rate of 1500 litres per hour, a 257 x 78 x 73mm size and a 23W motor. It's designed for larger or more active aquariums that need stronger water circulation, and it's worth pairing with hardy aquarium plants that tolerate a bit more flow.
View the I-1500 Internal Aquarium Filter

Frequently Asked Questions

How do I choose the right flow rate for my aquarium filter?

Match the filter's flow rate (litres per hour) to your tank's volume and how heavily it's stocked — larger or more heavily stocked tanks generally need a higher flow rate. The I-Series ranges from 370L/h up to 1500L/h, and all models have adjustable flow control so you can fine-tune output once installed.

Are these filters suitable for both freshwater and marine aquariums?

Yes, all four I-Series filters (I-300, I-500, I-1000 and I-1500) are designed for use in both freshwater and marine aquarium setups.

What does the adjustable flow control do?

It lets you reduce or increase the filter's output to suit your tank's inhabitants, from gentler flow for community tanks with less current-tolerant fish to stronger circulation for more active aquatic environments.

How much space do these filters take up in a tank?

They're compact internal filters, ranging in size from 162 x 50 x 52mm for the I-300 up to 257 x 78 x 73mm for the I-1500, designed to fit into smaller aquariums without taking up excessive space.