Fluval SEA CP Circulating Water Pump

• Four sizes, one mounting system – CP1 through CP4 all use the same magnetic mount, so it's easy to size up as the tank grows.
• Rated flow delivered at the pump – submersible and unplumbed, so there's no head height eating into the number on the box (see Performance below).
• Broad, low-turbulence flow – designed to keep detritus in suspension for the filter rather than blasting livestock.
• Compact footprint – sits inside the tank rather than in a sump or cabinet.
• Low running cost – 3.5–7 W across the range.

Sizing guide only – a tank with heavy rockwork, a deep sand bed or a lot of hardscape will want circulation toward the higher end of the range for its volume, not the minimum.

Because the CP pumps aren't plumbed through a hose, filter or sump, there's no head height for the flow to fight – unlike a canister filter or sump return pump, whose litres-per-hour rating drops sharply once water has to climb through pipework. The rated flow on each CP model is delivered essentially at the outlet, inside the tank, which is why Fluval doesn't publish a separate head curve for this range: there's very little head to curve against. Actual in-tank flow still spreads and slows with distance and any obstructions in its path, so aim the outlet across open water rather than directly at rockwork, substrate or livestock.

Suitable for freshwater and marine display tanks needing broad circulation – reef tanks, planted tanks, and community setups with a deep sand bed or heavy hardscape. Not a substitute for mechanical or biological filtration; it moves water, it doesn't clean it. Not recommended pointed directly at bettas, fry, or other slow, delicate swimmers at close range – position it to circulate the tank, not to blast one corner.

Pump body, magnet mount and low-voltage power lead. Does not include a controller – output is fixed per model rather than app- or dial-adjustable.

A second CP unit angled from the opposite corner, for cross-flow in larger or heavily aquascaped tanks. Fluval Sea return pumps where plumbed sump flow is also needed.

Covered by Fluval's standard warranty against manufacturing defects, in addition to your rights under Australian Consumer Law.

Why doesn't this page show a head curve like a return pump?

Head curves matter when a pump has to push water up through plumbing – a sump return, for example. The CP pumps sit directly in the tank with no hose or lift, so there's no meaningful head to chart; the rated flow is close to what leaves the outlet.

Can I run two CP pumps in one tank?

Yes – running two smaller units from opposite corners for cross-flow is a common way to avoid a single dead spot rather than sizing up to one large pump.

Is the flow adjustable?

Output is fixed per model – Fluval doesn't publish a variable flow control for this range, so size selection is by tank volume rather than by dialling one unit down.

Will it disturb a sand bed?

Broad, indirect flow is the design intent, but aim and distance both matter – start with the outlet angled across the tank rather than down at the substrate, and adjust from there.