Green birds nest browning

[BrettDS]

Any thoughts on why this green birds nest might be turning brown? This picture was taken shortly after I bought it...

And this one was taken 3 months later

Clearly I've had a lot of growth, so I'm happy about that, but it seems to have lost much of it's green. I have 3 gen 3 ecotech radion XR30W pro's above the 220G tank. I'm using regular instant ocean salt. I keep the salinity at 35ppt and have an auto water change system that changes about 2G/day. I'm using the BRS two part supplement to keep my calcium at about 450ppm and my alkalinity at about 8.9dkh (both salifert tests). Magnesium is 1350 and nitrates and phosphates are undetectable (salifert magnesium and nitrate tests and hanna lr phosphate checker)

About the time I added this coral I was having an issue with corals bleaching and it seemed like my lights may have been too intense, so I significantly cut back the intensity of the lights. This resolved the bleaching issues I was having, but I'm wondering if I may have cut them back too much.

Any thoughts on what I might be able to do to help get this greener?

 

[ryeguyy84]

how far back did you cut the lights? what percentage were they before and after?

 

[BrettDS]

Green birds nest browning

how far back did you cut the lights? what percentage were they before and after?

It was a pretty significant change. I have the lights on a curve in an attempt to mimic natural sunlight as much as possible. Before the change the lights hit a max overall intensity of 90% and the curve looked like this:

Now they hit a max of 65% and the curve looks like this:

But the change was actually even more significant than just the overall intensity because at the same time I changed the color temperature from 12K to 18K for the entire photo period. This had the effect of dropping the white, red, and green channels from 100% to 45%.

So like I said, it was a pretty big change, but it definitely does seem to have helped as corals are no longer bleaching and dying and I didn't lose any of the corals that had been surviving under the higher light levels. At the time I made the change I saw a post that said it's much easier to kill corals with too much light than not enough light, so I decided to go way down and see how things went.

I've also still been seeing good growth rates on the corals in the tank even though the lights have been at these lower levels for a good 5 months or so.

However, after 5 months it's probably worth re-evaluating and maybe trying to raise the levels a bit.

It's also worth noting that this birds nest was added after I made the light intensity changes.

 

[ryeguyy84]

your graph looks very similar to mine, I top out at 66% i haven't tried any higher for fear of bleaching. I'm far from an expert but i've been using my monti's to tell me when I need to add some nutrients to the tank. When they go from a bright orange to a sort of pale orange/pink I add a few drops of amino acids and they color back up. Maybe you have the same problem? My phosphates are around .02 to .04 on the Hanna, I think if yours reads nothing maybe they are starved for nutrients.

 

[Joey_bananas420]

i fragged my green birds nest and moved most of the frags to my frag tank but I kept one piece and put it in my display refugium cause it grows so fast I figured why not. I put a lot of fast growin Xenia and zoas green star stuff like that in there. So the frag went from under my kessils to under my 250 watt mh 20k forget the brand of bulb right now. And it turned brown within a few weeks. The display refugium is plumbed into my main display so it's all the same water just different lights. Just my experience ohh yeah none of the frags in my frag tank turned brown they were under kessils also

 

[markalot]

It's starved and needs more food to color up IMO. I see plenty of coraline but the rocks are super clean.