How to Position a Wavemaker for Even Reef Tank Flow

A customer brought in photos of his 300 litre mixed reef last month. Sand dunes had formed on one side of the tank, his acropora tips were bleaching on the flow-facing edge, and a torch coral three inches away wasn't moving at all. One pump, wrong spot, wrong angle. That's the whole problem in a nutshell, and it's fixable in an afternoon without buying more gear.

Wavemaker placement gets treated as an afterthought because the units are small and the instructions say "mount anywhere on glass." Technically true. Practically, where and how you mount it decides whether your corals get gentle, randomised movement or a sandblasting on one axis and a stagnant pocket on the other.

What you need

• A DC controllable wavemaker (Ecotech Vectra or Red Sea ReefWave both work well for tanks 150 to 400 litres)
• A magnetic or external mount rated for your glass thickness
• A tape measure
• Ten minutes of watching the water before you commit to a spot

Steps to get flow right

1. Mount high, not centre. Position the pump in the upper third of the water column, roughly 5 to 8 cm below the surface. High placement lets flow spread and drop naturally instead of firing straight into rockwork or substrate.
2. Angle it 10 to 20 degrees downward. Dead flat horizontal flow tends to hug the glass and create a fast lane along one wall. A slight downward tilt pushes water into the display and lets it bounce back diffused.
3. Aim for the opposite corner, not the opposite wall. Corner-to-corner flow travels further before it collides with glass and rebounds, which is what actually reduces dead spots rather than just moving them.
4. Use random or reef crest mode, not straight pulse. Constant one-direction flow trains coral tissue to lean and can gas-bind SPS tips over time. Random modes on the Vectra or ReefWave app cycle direction and intensity, which mimics natural surge far better than a fixed jet.
5. Dial back power near sand. If you're seeing dunes or exposed glass at the base, drop output 15 to 20 percent or raise the unit another few centimetres. Sand should shift slightly with gravel vacuuming, not migrate across the tank overnight.
6. Check LPS separately from SPS. Torches, frogspawn and hammer corals want gentle, indirect movement, not a direct blast. Place them out of the main flow line, closer to a return outlet than a wavemaker's direct path.

A note on gyre-style flow

If you're running a tank over 250 litres with a lot of open swimming space, a single directional pump can still leave the far end sluggish. This is where gyre-style units earn their keep, pushing a wide, wall-hugging current that circulates the whole footprint rather than firing one jet across the middle. Worth considering as a second unit rather than a replacement for your main wavemaker.

For mounting, the Ecotech RMS slide system lets you reposition a Vectra along the rear rail without redrilling or juggling magnets, handy when you're still testing angles over the first week.

Once you've got placement sorted, browse our wavemakers range for units and controllers that suit tanks from 100 to 500 litres, including the Ecotech Vectra and Red Sea ReefWave, plus the Ecotech RMS Slide for tool-free repositioning.

Prices mentioned are accurate at the time of publishing and are subject to change. Please check the product page for the current price.