Fluval Sea T5 Marine Glo High Output Tube

• Dominant blue actinic spectrum – supplies the actinic wavelengths that drive coral and invertebrate fluorescence, the colour "pop" you don't get from a plain white tube.
• Supports coral photosynthesis – the actinic peaks sit within the range photosynthetic corals and other invertebrates use, alongside your main white/blue spectrum tube.
• Standard T5HO format – drop-in replacement for any T5 High Output fixture built for the matching length and wattage, not limited to Fluval fixtures.
• Three lengths – 55 cm/24 W, 85 cm/39 W and 115 cm/54 W, so you can match wattage without cutting down a fixture.

Match the length and wattage to what your fixture's ballast is rated for – a T5HO ballast is wattage-specific, so fitting a 39 W tube to a 24 W-rated fixture won't give extra output and may shorten the tube's life.

Fluval doesn't publish a colour-temperature (Kelvin) or lumen figure for the Marine Glo line specifically – it's marketed and sold on spectrum description (dominant blue/actinic) rather than a Kelvin rating. If you need a specific Kelvin number for a controller or comparison, check with Fluval support before buying rather than assuming a figure.

• Suitable for: marine and reef tanks running T5HO fixtures, as a supplementary actinic tube alongside a white/full-spectrum T5HO tube.
• Not suitable for: freshwater planted tanks needing PAR for plant growth – this is an actinic-heavy marine tube, not a plant-growth spectrum. Not a standalone light source for a reef – pair it with a white spectrum tube for a usable colour balance.

T5HO tubes lose usable spectral output well before they stop lighting up. Many reef keepers replace actinic tubes on a roughly annual cycle even though they still glow, because the actinic peak fades faster than visible brightness – Fluval doesn't publish an exact figure for this tube, so treat that as general practice rather than a manufacturer number. Wipe dust and salt creep off the tube and reflector regularly, since both cut delivered light more than the tube's own ageing.

A white or full-spectrum T5HO tube in the matching length, to balance the actinic-heavy output of this tube into usable reef lighting.

Covered by Fluval's standard manufacturer warranty against defects, in addition to your rights under Australian Consumer Law. Small parcel item – glass tube, packed carefully.

Will this fit a non-Fluval T5HO fixture?

Yes – T5 High Output is a standard lamp format. Match the length and wattage to your fixture's ballast rating and it will fit regardless of brand.

How often should I replace it?

Fluval doesn't publish a fixed figure. As a general reef-keeping guideline, actinic T5HO tubes are often replaced annually since spectral output fades ahead of visible brightness – watch for corals looking duller under the same lighting as your cue.

Can I run this as my only light?

Not for a reef tank – it's an actinic supplement. Run it alongside a white/full-spectrum T5HO tube for a usable colour balance and enough PAR for corals.

Does it suit a freshwater planted tank?

No – it's spectrum-tuned for marine actinic colour, not plant growth. Use a dedicated plant-spectrum tube for a freshwater planted setup.