Zoo Med 24 Watt T5 HO ReptiSun 10.0 UVB Lamp, 2pk Review (2026)

Who this mid-length tube fits

This lamp is built for a 22 inch T5 High Output fixture, a common size on mid-range reptile hoods, which makes it a practical match for enclosures that are not quite long enough to need the 34 inch version of the same ReptiSun 10.0 line but are still larger than a small starter tank. Zoo Med positions this High Output tube for desert-dwelling species such as bearded dragons, uromastyx and tortoises that benefit from strong UVB across a basking area rather than a dim ambient glow. Because the pack includes two tubes, it suits a keeper running a single enclosure who wants a ready spare on hand, or two smaller tanks that both use the same 22 inch fixture size.

Wattage, output and fixture requirements

Each tube is a 24 watt T5 High Output lamp at 22 inches long, carrying Zoo Med's 10.0 UVB rating and manufactured in Germany. Like the rest of the T5 HO ReptiSun line, it is described as twice as strong as Zoo Med's standard ReptiSun 10.0 fluorescent tubes, which is meant to help UVB penetrate a mesh screen top rather than being blocked before it reaches the basking spot. The bulb does not include a hood or ballast, so it only works with a T5 High Output fixture sized for a 22 inch tube specifically, since T5 HO tubes use a different pin and ballast setup than T8 or compact fluorescent bulbs and are not interchangeable between fixture types.

Placement, replacement and daily care

Because this is a High Output tube, mounting distance and any screen between the bulb and the basking spot both affect how much UVB actually reaches the animal, so measuring exposure with a UV meter, or following Zoo Med's published distance guidance, is worth the extra step rather than guessing. UVB output fades well before the tube stops producing visible light, so plan to swap it out on a routine schedule, which is where the second tube in this pack becomes useful as the next scheduled replacement rather than an emergency backup. Keep the tube dry and clean of dust or substrate buildup, since a dirty tube surface can block some of the UVB it is producing.

How it compares with the longer 34 inch version and other bulbs

In the site's UVB bulbs guide this 22 inch, 24 watt pack ranks second out of seven, just behind the longer 34 inch, 39 watt version of the same ReptiSun 10.0 T5 HO line, which suits enclosures too long for this tube to cover evenly. Both rank ahead of Zoo Med's standard linear 10.0 fluorescent tubes and its compact fluorescent 10.0 bulb, which produce noticeably less usable UVB across a basking area despite fitting smaller, cheaper fixtures. Choosing between the two T5 HO lengths mostly comes down to matching the tube to your existing or planned fixture rather than one being a strictly better product than the other.

Verdict and who should choose differently

Choose this 2 pack if your hood is built for a 22 inch T5 High Output tube and you are keeping a desert species like a bearded dragon or uromastyx that needs strong UVB across a mid-size basking area, with the spare tube covering the next scheduled swap. If your enclosure or fixture runs longer, the 34 inch, 39 watt version of this same ReptiSun 10.0 T5 HO line will cover the basking area more evenly than stretching this shorter tube across it. Keepers of shade-preferring or smaller-bodied species that do not need this level of UVB intensity may be better served by a standard, lower-output ReptiSun bulb instead.

Frequently asked questions