T5 bulbs for coral coloration

[emeraldh]

I've been running T5s for about six months now, but my Acros just don't pop like they did under LEDs. Anyone else notice this? Running four bulbs, two blue plus, one coral plus, one purple plus. Tank's a 75g with a 20g sump, salinity at 1.025, temp 78.

[boldo]

T5s can be tricky with Acros. What's your PAR reading at the coral's location? I've found they need at least 300–350 PAR under T5 to match LED intensity. Also, how old are the bulbs? They lose spectrum after 9–12 months.

[southpaw1]

Boldo's spot on about bulb age. I replace mine every 10 months religiously. Also, try swapping the purple plus for another blue plus. Purple can wash out reds in some setups. My SPS tank's 120g, same bulb combo but three blue plus, one coral plus.

[Kalimero]

T5s can be tricky with Acros. What's your PAR reading at the coral's location? I've found they need at least 300–350 PAR under T5 to match LED intensity. Also, how old are the bulbs? They lose spectrum after 9–12 months.

Yep, PAR's key. I run a hybrid T5/LED setup to get the best of both. Maybe try supplementing with a cheap LED bar for pop? My Acros love the combo.

[steadsly]

Ditch the purple plus, dude. That thing's sketchy for SPS. My buddy ran it and his montis browned out. Stick to blue plus and coral plus, maybe throw in an actinic if you're feeling fancy. Tank's 40g breeder, no sump, just a HOB.

[Scalekeeper1]

Bulb age and spectrum matter, but don't overlook water quality. What's your alkalinity at? Acros need stable alk above 8 dKH to color up properly. Mine sit at 9.5 dKH, 450 PAR, and they're neon under T5s.

[familylove]

My kids love the purple plus, but yeah, it's not for everyone. Maybe try a different brand? I've had luck with ATI bulbs. Also, how often do you feed? My Acros perk up with weekly amino doses.

[starwave9]

Bulb age and spectrum matter, but don't overlook water quality. What's your alkalinity at? Acros need stable alk above 8 dKH to color up properly. Mine sit at 9.5 dKH, 450 PAR, and they're neon under T5s.

Alk's huge. I crashed mine once and everything went pale. Now I dose daily to keep it at 8.5 dKH. Also, check your magnesium—should be 1350–1400 ppm for best color.

[tokai]

T5s are solid, but they're not LEDs. If you want that insane pop, you might need to hybridize. I run two T5s and two Radions, and my Acros are stupid bright. Tank's a 60g cube, 1.026 salinity, temp 77.

[emeraldh]

Thanks for the tips, everyone. Gonna test PAR and swap the purple plus. Bulbs are eight months old, so maybe time for a refresh. Appreciate the alk and mag reminders too—I've been slacking on testing those.