Zoo Med ReptiSun 34-Inch 10.0 UVB T5 High Output Lamp, 2 Pack Review (2026)

Who this long UVB tube is built for

This lamp is sized for a long enclosure, roughly the length of a 34 inch T5 HO fixture, which makes it a fit for desert-adapted reptiles like bearded dragons, uromastyx, monitors and tegus that are typically housed in wide, ground-level terrariums rather than tall vertical ones. Zoo Med markets this High Output tube as twice as strong as its standard ReptiSun 10.0 fluorescent line, so it suits keepers who need UVB to reach across a wider basking area or penetrate a mesh screen top rather than an open-top glass tank sitting close to the bulb. The 2 pack format means you get a working spare on hand for when the first tube reaches the end of its useful life, without waiting on a reorder.

Wattage, output and what the fixture needs to be

Each tube in this pack is a 34 inch, 39 watt T5 High Output lamp carrying Zoo Med's 10.0 UVB rating, made in Germany. It does not include a fixture or hood, so it only works if you already own, or plan to buy, a T5 HO hood built for a 34 inch tube specifically, since T5 HO tubes are not interchangeable with standard T8 or compact fluorescent fixtures. Zoo Med designs this High Output line for terrariums up to about 30 inches tall when the bulb is mounted in an open or screen-top hood, with the manufacturer providing distance charts on the packaging to guide safe basking-zone placement for different species.

Things to check: installation, compatibility and handling

Like other fluorescent UVB tubes, output drops well before the bulb stops producing visible light, so plan to replace each tube on a routine schedule rather than waiting for it to visibly dim or burn out, and keep the second tube in this pack as that scheduled replacement instead of a backup for a sudden failure. Mounting height matters more with a High Output tube than a standard one, since the increased intensity can overexpose a species that naturally lives in filtered shade if it is placed too close or without any screen attenuation. Zoo Med backs the lamp with a 1 year warranty, which is typical for fluorescent UVB tubes in this category.

How it compares with shorter Zoo Med tubes and rival options

In the site's UVB bulbs guide this 34 inch pack ranks first out of seven, just ahead of the shorter 24 watt, 22 inch version of the same ReptiSun 10.0 T5 HO line, which suits a mid-size enclosure rather than a long one. Both outrank Zoo Med's older compact fluorescent and standard linear 10.0 options, which produce less usable UVB across a wide basking area even though they are cheaper and fit smaller fixtures. The main choice within Zoo Med's own lineup comes down to matching tube length to your fixture and enclosure width, since a 34 inch tube is wasted in a short tank and a short tube will not cover a long one.

Verdict and who should pick a different length

Pick this 2 pack if your enclosure and fixture are built for a full 34 inch T5 HO tube and you are housing a desert species that benefits from strong, wide-reaching UVB, such as a bearded dragon or uromastyx in a long terrarium. The included spare is a genuine convenience for the scheduled replacement every UVB tube needs. If your terrarium or hood is shorter, the 24 watt, 22 inch version of this same ReptiSun 10.0 T5 HO line is the better match, and shade-dwelling or nocturnal species are generally better served by a lower-output bulb with careful distance and shading rather than this High Output tube.

Frequently asked questions