VorTech MP40 vs AI Nero 5: which wavemaker?

The VorTech MP40 and the AI Nero 5 are the two powerheads most reefers cross-shop in the $250–$450 range. They're closer than the price gap suggests — both are Mobius-controlled propeller pumps from the EcoTech family — but they differ in three ways that decide the purchase: flow ceiling, motor placement, and battery backup.

Head to head

All specs and prices verified July 2026.

Both are controllable propeller pumps; figures are each pump's rated maximums. The MP40's motor sits outside the tank; the Nero 5 houses everything in one in-tank unit.

Where each one wins

Flow ceiling. The MP40 tops out at 4,500 GPH versus the Nero 5's 3,000. On a tank up to about 100 gallons the Nero 5 has plenty of headroom; past that, or for SPS that wants 40–60× turnover, the MP40's ceiling matters.

Motor placement. The MP40 uses a dry, magnet-coupled motor that mounts on the outside of the glass — nothing but the wet-side rotor is in the water, which some keepers prefer for aesthetics and for keeping heat out of the tank. The Nero 5 puts the whole unit, controller included, inside the tank on a magnet. Fewer cords, but more hardware in view.

Price. The Nero 5 is $172 cheaper. For a single powerhead on a mixed reef under 100 gallons, that's a real gap with no performance penalty.

The battery-backup gap most people miss

Here's the buying detail that doesn't show up on spec sheets. If keeping flow alive during a power outage matters — and for SPS it does — the two pumps are not equal:

• The MP40 runs natively on the EcoTech Battery Backup ($259.99), which powers VorTech pumps directly and keeps them running at reduced speed for many hours during an outage.
• The Nero 5 has no clean battery-backup path. The EcoTech Battery Backup powers EcoTech pumps only. And the popular near-universal alternative, the IceCap Battery Backup v3 ($169.99), explicitly lists the AI Nero as not compatible.

So if outage protection is on your list, the MP40 has a supported answer and the Nero 5 does not — a factor easily worth part of the $172 price gap for an SPS keeper.

Who should buy which

Buy the AI Nero 5 ($259.99) if:

• Your tank is 100 gallons or less
• You want the lowest price with no real performance loss at that size
• You're fine with an all-in-tank unit and don't need outage backup

Buy the VorTech MP40 mQD ($431.99) if:

• Your tank is over 100 gallons, or SPS needing 40–60× turnover
• You want the motor out of the water
• You want native EcoTech battery-backup support
• Your glass is up to 0.75 inches thick (the Nero 5 tops out at 0.63)

Bottom line

For most mixed reefs under 100 gallons, the Nero 5 is the smarter buy — same Mobius ecosystem, plenty of flow, $172 cheaper. Step up to the MP40 for larger or SPS tanks that need the higher ceiling, the external motor, or battery backup. Not sure how much flow you actually need? Start with the flow calculator, see the full field in best wavemaker, and size your whole system in the System Builder.

Flow ratings, dimensions, ecosystem and battery-backup compatibility verified July 2026 (manufacturer sites, Bulk Reef Supply, CoralVue, AquaCave). Battery-backup compatibility is from IceCap/CoralVue and EcoTech published compatibility lists. Re-check pricing before purchase.

Frequently asked questions

What's the real difference between the MP40 and the Nero 5?

Three things decide it: flow ceiling, motor placement and battery backup. The VorTech MP40 mQD pushes 4,500 GPH from a dry external motor for $431.99; the AI Nero 5 pushes 3,000 GPH from an all-in-tank unit for $259.99, which is $172 less. Both run on Mobius, so either drops into an EcoTech or AI-controlled tank.

Is the MP40 worth $172 more than the Nero 5?

On a mixed reef under 100 gallons, often not — the Nero 5 has plenty of flow headroom there with no performance penalty. The MP40 earns the premium when you need its higher 4,500 GPH ceiling for a larger or SPS tank wanting 40–60× turnover, want the motor out of the water, or need battery backup.

Which should I buy for a tank under 100 gallons?

The AI Nero 5 ($259.99). It is rated for 40–100 gallons, gives you the lowest price with no real performance loss at that size, and runs on Mobius — provided you are fine with an all-in-tank unit and don't need outage backup.

Can I run a battery backup on either pump?

Not equally. The MP40 runs natively on the EcoTech Battery Backup ($259.99), which keeps VorTech pumps going at reduced speed for hours during an outage. The Nero 5 has no clean path — the EcoTech unit powers EcoTech pumps only, and the popular IceCap Battery Backup v3 ($169.99) explicitly lists the AI Nero as not compatible. Plan for that if you keep SPS.

Does glass thickness matter for these pumps?

Yes, if your tank has thick glass. The MP40's magnet-coupled motor handles glass up to 0.75 inches, while the Nero 5 tops out at 0.63 inches. On a thicker-walled tank the MP40 is the one that will actually mount.