Two male bearded dragons, one room — stress-free lighting

Two male bearded dragons in the same room is a setup that needs managing carefully — even through glass, males absolutely see each other and can spend hours doing threat displays, which is chronically stressful and suppresses appetite and immune function. Before I get into the lighting side, bad lighting is actually the most common husbandry mistake with bearded dragons overall — wrong UVB output or basking temps that are even a few degrees off lead to metabolic bone disease and slow immune decline that owners often don't spot until real damage is set in. So let's sort both issues together. What size are their enclosures, what bulbs are you running in each (brand and wattage), and how old are the two dragons?

Your lighting kit is actually solid — Arcadia T5 12% and halogen floods are exactly what I'd recommend for adult dragons in a 4x2x2, so that's not your problem here. The issue is almost certainly visual — one male clocking the other's enclosure lighting up and reading it as a rival waking up and staking territory. The glass surfing at light-on is a classic stress response to that. Two things will fix this: a physical visual barrier between the enclosures so they genuinely cannot see each other at all, and staggered light schedules so they're not both 'waking up' simultaneously which amplifies the territorial response. Are the enclosures currently touching side by side, or is there any gap between them?

The foam board is a great immediate fix — put it in today, it'll make a noticeable difference quickly. On the timers: 30 minutes of stagger is enough to break the synchronised wake-up trigger, yes. And you don't need two separate units. The Inkbird IBS-M1 smart power strip with individual socket control is what I'd go with here — it lets you set each socket to its own schedule from your phone, so you can run dragon one's lights 7am to 7pm and dragon two's 7:30am to 7:30pm from a single device. It also gives you real-time monitoring so if a bulb fails overnight you'll see it in the app rather than coming down to a cold dragon. It's around £35 on Amazon UK and handles the wattage of halogen floods without any issue.

Stagger both. The UVB tube light output is visible to them and it's the full enclosure illuminating that triggers the territorial response — not just the basking spot heat. Run both sets of lights on the same staggered offset so each dragon's entire environment comes on and goes off 30 minutes apart. On the Inkbird strip you'd just assign the UVB ballast and the halogen for enclosure one to sockets 1 and 2 with the same schedule, then enclosure two's gear to sockets 3 and 4 with the offset schedule. Tidy and simple. Once the foam barrier is up and the schedules are offset, most owners see the glass surfing drop off within a few days.

Good plan — foam board first, it costs nothing and you'll likely see a calmer dragon by tomorrow morning. Once the Inkbird is set up, give it a week and see how both dragons are eating and behaving. If the glass surfing has stopped and appetites are normal, you've cracked it. If one is still showing stress behaviours after the visual barrier is solid, it's worth reassessing the shelf position — sometimes even a small gap in the barrier lets them clock movement in the other enclosure. Feel free to come back if anything's not settling down.