Too much UV light? Or flow?

[kimros1986]

I have a couple of sps "rarities" (acropora tenuis walt disney and sunset millepora) that thrives in my frag tank (FT) but fades in my display tank (DT).
When I got those two colonies I fragged them down after a couple of weeks, as a "precaution". Some was placed in the FT and some in DT.
All of them were placed in between 300-350 par of light.
After a while the frags in DT started fading, losing both color and PE. So I snapped them off and put them in the frag tank. After a while they started to both get their color and their fluff back...

Both DT and FT are connected to the same sump, so water parameters should be all the same.

FT flow is return pump and a mp10 at half power. Frag tank is quite small, only 60x30x30cm.

DT flow is two maxspect 350 at half power (half dirty) and a mp40 at half power. DT is a red sea reefer 350 (120x50x55 cm).

FT has one single hydra 26hd, at around 75%, brs ab+ setting.

DT has two hydra 52hds at around 25% (also brs ab+ setting) , two orphek or3 blue plus 90 cm, two ati actinic t5 39w bulb (one changed a couple of months ago).

PAR is measured with a seneye.

Mind you that I do have other sps really thriving in the DT, but it bugs me out that I can't get these two rarities to show its best sides. I do have one rarity, a tenuis rainbow, that is really colorful and happy (that I know of).

Could it be that there is too much UV light for some corals, with the two actinic bulbs on top of hydra with ab+ settings and the orphek?
Or could it be too much flow? Is that possible? None of the corals are blasted/in front of any streamer/return pump outlet...

Please help me guess?

 

[Saltyreef]

I have 2x hydra 52s over my display and my stuff grew way better with 2x hydra 26s.
I think the 52s may even be overkill dimmed.

Ive had to dial the 52s waaaaaaay back.

 

[kimros1986]

I have 2x hydra 52s over my display and my stuff grew way better with 2x hydra 26s.
I think the 52s may even be overkill dimmed.

Ive had to dial the 52s waaaaaaay back.

Yeah it feels like if I would turn them down a little bit more I might as well turn them off all together. Maybe trade them for 3 26/32hd.
It feels like I would get a lot less spread with "only" the 26hd as main led lights.

 

[Charlie’s Frags]

My Tenuis grow way better under my hydra 52 HD’s than they do under my 26 HD’s and prime 16 hd. But I only have like 70 tenuis.

 

[Saltyreef]

My Tenuis grow way better under my hydra 52 HD’s than they do under my 26 HD’s and prime 16 hd. But I only have like 70 tenuis.

I think layout & depth are considerate variables when choosing the proper fixture.

 

[Charlie’s Frags]

I think layout & depth are considerate variables when choosing the proper fixture.

Agreed….and application. My 2-52hds are mounted 16” above a 50g cube. My prime 16 hd is on a 6g cube for frags. The prime had to be mounted lower with more white to produce similar par as the 52 hds, but that combo burns some Tenuis that handle much higher par from the 52 hds. Not a big fan of the prime 16. Or the 26 hds.