The short answer
AI Nero 3 is the compact smart broad-flow benchmark. Tunze 6040 offers the finest low-to-high control range in a small body. Tunze 6045 is the simple-value choice. Maxspect XF330 is the long-tank cross-flow option, especially when one point source leaves dead zones.
| Model / checked price | Published flow | Power | Control / glass | Planning fit |
|---|---|---|---|---|
| AI Nero 3 £175–£183 | Up to 7,570 l/h | Variable, 20W max | MyAI app or onboard controller; 13mm glass | Compact broad flow for nano-to-medium displays |
| Tunze Turbelle nanostream 6040 £152–£170 | 200–4,500 l/h | 1.5–13W | Turbelle controller / Tunze Hub; 15mm glass | Tiny controllable pump with unusually wide range |
| Tunze nanostream 6045 £73.90 | 1,500–4,500 l/h | 5–7W | Fixed-speed; 15mm glass | Simple low-cost circulation where app control is not needed |
| Maxspect Gyre XF330 CE £300 single; £410–£450 twin | Up to 9,000 l/h | 5–35W | Controller/app options; 15mm standard, 20mm reinforced | Cross-flow for long tanks; larger and more maintenance-intensive |
One pump or two?
One pump is simpler and cheaper. Two pumps can create more even movement, alternate pulses and reduce the temptation to blast one side of the aquarium. For a long tank, two moderate sources may be more useful than one large source—even when the total label flow is lower.
Placement beats the number
Start with flow across the upper rockwork and surface, then look for settled detritus and coral tissue movement. Avoid a direct high-speed jet into a fleshy coral. Clean cages and propellers regularly: an algae-coated flow pump is not delivering its advertised pattern.