reefraf

Well I going to start off by saying it could be anything. I first thoughts are LED lights in general. I'm not 100% sold on this technology. Second thought is your corals need more nutrients, since your nitrates are zero. How often do you clean your front glass on your tank ?

i clean the glass every 4-5 days

How often do you feed your fish?

STN (slow tissue neucrosis) working its way up the base of the coral is almost always alkalinity-related. If it goes up and down often, the coral won't tolerate it indefinitely.

Explain your lighting in detail. How high is it above the water? How long do they run each day? How far is the distance from the LEDs to the corals in question? How long are you running the moonlights?

I feed sparingly twice a day a variety of pellets, flakes, and frozen.

My alk has always been on the low side, i have slowly been raising it up since i started with the BRS 2 part about 2-3 weeks ago. the coral problems started even before i fiddles with the alk.

My tank is 30x30 and 25 inches deep. in order to get the light to cover the tank, i mounted the lights 13 inches above the water. Currently have the lights come on at 7am and off by 10pm. In the afternoon is my main light period where the lights ramp up for 5.5 hours. the blues get to 100% and the whites max at 50%. At these intensitys is where my carolina colored up purple again. My corals are about 1/3 of the way up from the bottom. Currently, i do not run my moonlights.

With the history of lower alkalinity, and now with you learning and adjusting daily, the corals are going to react accordingly. While you've seen some losses, as the water parameters stabilize, your corals should improve. There's nothing you can do about the bases, as corals grow upwards the majority of the time. The new tips should emerge and color will improve again.

I think you are running your lights too long. Currently you have a 15 hour cycle even if it isn't all of them. I'd cut it down to 11 hours per day from start to finish, and shorten the 'high noon' phase a bit. If you opt to run moonlighting in the future, just turn it on for an hour or two, then off again. Let the corals sleep just like you do - in the darkness.

Seems like lighting might still be the issue. How long have these new lights been over the tank ? Have they always been 13" above the water ? LED bleaching is very common. When I first placed sps frags under my LED par38 spotlights in my frag tank, I noticed color fading on some of my sps's. Some corals did fine. Green and blue corals did the best, red corals bleached within a week. What was your old lighting (i.e. T5, PC or MH) ? Light acclimation is very important when introducing coral to intense LED light.

Also sps's need random flow. In the ocean reefs, if you watch the massive currents during the day you will see this. One moment there is calm, the next moment a million gallons water goes rushing across the reef (moving left to right). Then a moment later another million gallons of water rushes back (right to left). This is what brings nutrients to the corals, and at the same time removing waste. What are you using for flow ? What type of filtration (protein skimmer) ?

The lights has been over the tank since January. I added the corals after i got the LEDS. They have always been the same height. As i mentioned my tank is 30x30 and 25 deep. I have 2 mp40's on 2 adjoining walls. I believe i have plenty of random flow. And i have about 6-7x turnover through my sump.

My smallest coral was the blue tenius. is was turning white about half way up. Now this morning, the top parts that were still blue are basically peeling off and blowing in the current. Is that what STN does?

i have scaled my photo period back to 11 hours, still with a "high noon" period. The max for my whites is never over 50% intensity, the blues get to 80%.

This is what RTN looks like: http://www.dfwmas.org/Forums/viewtopic.php?f=9&t=18432
STN is much slower, like watching grass grow - the white area spreads upwards so slowly that you wonder if it is getting worse or if you simply don't remember it being that large.

Great post, thanks. That is what mine did, but it started slowly, they ripped up. Can other corals catch this? Why does this happen?

If your corals are loosing tissue from the bottom up, it's not your lights. 30" cube with two mp40's ... How high do you have the mp40's cranked up ? My mp40 can rip the flesh off my corals 40" away from it ! What type of filtration (protein skimmer) ?

i have one about 40% off the bottom on reef crest cranked 85%. The other is about 6 inches under water and also on reefcrest cranked up about 75% I have a sump made by melev, and an aquac ev-180 skimmer. that works very well.

Also read my last comment on your blog.

http://www.reefaddicts.com/entry.php...levels?bt=3368