Turn it up and you get more flow from the same place. Change the wave pattern and you get the same plume, pulsing.
Angle it differently and the shadow moves with it.

Think of the pump as a torch and the flow as its beam. Rockwork in the way casts a flow shadow, and it obeys the same rule as a shadow on a wall: turn the torch up and the dark patch stays exactly where it was. What sets a shadow is where the light comes from — not how much of it there is.

That's why the detritus settles in the same corner every week. It isn't your pump. It's where your pump is mounted.

Housing is PETG throughout — chemically inert, with no additives of concern in an aquatic setting. No photopolymer resin anywhere near your water. The carriage is stainless, and the rail is hardened steel — which is what every recirculating-ball linear guide has to be, because the raceway must be hard and hard means less corrosion-resistant. That is precisely why the housing is built the way it is: the protection is the geometry, not the alloy.

That arrangement is the subject of UK patent application GB2619546.1, and the way the whole thing looks is covered by seven UK registered designs.

Designed and built in the UK, and assembled and tested by me. Units are covered by a UKCA declaration of conformity — covering electromagnetic compatibility and RoHS.

Measure front to back, inside the glass. That one number picks your unit.

A couple of clearances confirm it — they're on Will it fit.

You'll see it. Here's exactly how much.

It sits 77mm above the rim and extends 60mm back over the tank. Here it is on a white RedSea Reefer 250 G2, black on one side and white on the other, photographed in normal room light rather than in a studio.

It's printed in PETG on my own machines, one at a time, so there are fine layer lines if you look closely. That's the process, not a fault, and it's why your colour costs nothing extra and why this exists at all at these numbers.

If a completely clean rim is non-negotiable for you, this isn't your product — and that's a perfectly reasonable position to hold. If you'd trade a slim rail across the side of your tank for flow that reaches everywhere, it's the only thing that does this.

Black or white, same price, chosen at checkout.

The short answer is yes!

You cannot run a Fusion Flow with netting in place, or more specifically, without making an adaptation to the netting.

The arm travels through the space a net sits in. A single sheet of mesh across the whole top of the tank, and this unit can't both be there — so the net can either be adapted or, if practical for your setup, can come off.

It isn't a dead end. Framed, cut-to-size net kits are made for exactly this, and Red Sea's DIY Net Cover is the obvious one — its own instructions describe building the cover around rim-mounted equipment like lights and returns. You net around where the unit runs rather than over it: fit the unit at one end and net the rest, or run two, one at each end, and net the middle.

It's worth working this out before you order, not after. If you keep fish that jump — wrasses, gobies, anthias — decide where your net panels will go while you're still choosing a size.

It's a simple job now, versus a potential jumped fish later.

Then you have to feed through it. A net solves the jumping and immediately creates the next problem: getting food in without unclipping a panel twice a day. The usual answer is a feed port — a rigid ring that holds an opening in the mesh, so the net stays shut and food goes straight through.

I make one. Feed Port Pro, 75 mm, £14.95.

Please review our How it works page for all the details.

Please review our Will It Fit page for all the details.