Kenya Tree Coral Bleaching- Too much light?

[sledge760]

Up until the past month or so I have had numerous thriving Kenya Tree corals growing in my 156 Oceanic tank. Slowly, all have started bleaching and are completely bleached out. They are not dead but definitely do not look as healthy as there were and are all white. All parameters are good. I have 480 watts of T5 lighting and the corals are placed in the middle of the tank. Would 480 watts of lighting be too much?

nitrates: 15
nitrites: 0
ammonia: 0
ph: 8.4
phosphates: 0.1
mg: 1350
ca: 475

 

[InsaneClownFish]

Your Nitrates are .15, as in 15 parts per million?

Even with high Nitrates, the Kenya Tree should thrive. They're nearly indestructible.

My Kenya Tree grows like weeds in shaded areas of my 8ft reef with only 296w of T5. I also had frags in an expansion tank that I ran an old 400W halide with no reflector 2 or 3 times a week and they were fine.

My guess is you're cooking them with the light. Move them to the bottom of the tank or into shaded areas and see if they recover. Is the tank lighting new? Did you recently change the bulbs?

Also watch for temperature spikes this time of year. Hope this helps.

 

[sledge760]

Yes. Nitrates are .15ppm

Tank lighting is from 1/10. I am cutting down on the light. I stopped and spoke to a guy from a LFS who is one of the top coral guys in my area. He say's he is willing to bet the issue is too much light.

Temperature does spike up to 85-86F in the room when it gets hot.

 

[InsaneClownFish]

Agreed, light shock coupled with high temperatures. My tank sits around 78.

81 or 82 is even fine, but that 4 or 5 extra degrees will really stress most corals.

 

[Crustman]

Mine also bleached when my tank hit 86. 1 of 3 toadstools also bleached. Then I had an outbreak of cyano that went with it.

 

[drew1]

Were the kenya trees actually bleaching or just tightly closed up? I find that when they get hot (85+) they close up tight, which gives them the whitish appearance. Mine do fine at 82, but 85 they are unhappy. Much hotter and they start looking really bad. The light shouldn't be an issue, unless you just moved them from low light into a high light environment. Then they may be shocked. I have them under PC's and MH. They do fine under both.

 

[alancolinet]

At 85 degrees you'll start to damage those corals. Eventually they won't be able to recover if exposed to that high a temp for too long.

I would consider investing in a simple fan to blow over the top of the tank; you'd be surprised how much cooling a simple fan blowing over the top cools a tank. My small fan cools my tank by as much as 4-5 degrees.

The only real downside is increased evaporation.

 

[ONEmorBEER]

Drop that temp....slowly so you don't shock them. They don't need much light

 

[sledge760]

I have a large fan blowing on the whole tank and a small fan blowing across the top now. Most of the Kenya tree's have not recovered. They look like crap and are shriveled down to almost nothing. The temp is around 82-83F now. I took one of the lights off. I think I was blasting the tank with too much light for softies. It does not help that it was 102f yesterday and 101f today in Philly. I have an AC window unit two rooms away that helps a little.