Barren area in my tank?

[NanaReefer]

I don't know what else to call it. It started with my 5yr old Favia showing bleached areas on top and 2 smaller frags of the same Favia showing bleached areas as well. So I moved them off to the side and back. Not yet fully recovered but looking better than they were.
I've tried several types of coral in this same barren area. Within days and even hours all corals showed obvious signs of stress. Fungia, Favia, Chalice, Orange Pavona, have all been tried in this area. Results were loss of tissue color and polyp extension. Move them 5-8" away from that area and they're fine. So now I've got this big open space that I can't seem to put anything there. I am totally baffled! Right in the middle.

 

[spieszak]

You are running LED's right?
Have you tried starting something 5-8" and slowly moving it in? Could it be the LED is just super concentrated in that spot and things need 'extra' acclimation?

 

[NanaReefer]

Yes LED's. Of which I know very little about. I'll definitely give your idea a try

 

[Scooterman]

That was my first thought either in that spot too much light or not enough, especially if things goes well anywhere else. probably have a hot spot where your getting higher intensity in that area, I light meter would do the trick but probably not necessary. Acclimate as mentioned, creep crawl or restrict the light in that spot and slowly introduce it to whatever you decide to put there but wait until you have healthy corals to do this with.

 

[Blue Lip]

Is this spot directly under the led fixture? Do you dose iodine?

 

[NanaReefer]

Yes it's directly under the lights. No I don't dose iodine.

 

[tike]

Definitely a hot spot. How high of a % are you running your whites? I would try cranking back to about 40-50% and see if that works. Are there optics on your unit?

 

[NanaReefer]

12 1/2" from surface. 120 degree optics. Whites @15% max blues @55% max. And I just raised the % yesterday. Otherwise whites have been running @12% max for 2 months.

 

[Blue Lip]

That is the spot where you will get your highest par readings. Place corals that require strong light there. As you place a coral in a spot that has intense light, the coral may fade or look bleached. This happens because the host coral expels some of its symbiotic zooanthellae. Zooanthellae gives corals color. As corals loose their zooxanthellae they loose color. Zooanthellae is a photosynthetic algae that does several things for its host. Through photosynthesis zooxanthellae produce amino acids, glycerol, & glucose. Zooanthellae also produces oxygen for its host. When you place a coral in intense light, the zooanthellae produce more amino acids, glycerol, glucose, & oxygen. The increase of oxygen in the tissue of the host coral can reach toxic levels. The host coral will expell the zooanthellae to prevent toxic levels of oxygen within its tissue under strong light leaving corals looking bleached. This is where iodine is important. Iodine aids the coral in expelling excess oxygen from its tissue. The coral keeps the zooanthellae & color under strong lights when adequate levels of iodine are present. Iodine is like sunscreen for your corals. Iodine is also needed by crustaceans to molt.

 

[NanaReefer]

Would you recommend me picking up an iodine test kit?

 

[Blue Lip]

I have tried salifert & red sea but found them difficult to test. I would love to get some type of colorimeter for iodine but i think they are made for fresh water only. I could be wrong though & if someone knows please share. Iodine should be dossed SLOWLY! Dont be surprised if you have crustaceans molt after you dose iodine.

 

[NanaReefer]

Well I'm not real inclined to dose anything I cannot test for. RedSea has an iodine kit, may look into that.
You think at 5g bi-weekly my WC aren't enough to replace trace elements? My tank is all SPS/LPS.
About +- 47g total water volume.

 

[Blue Lip]

I have the red sea test kit & find it difficult to get a reading even after dosing. You may have better luck than me though. Google information on iodine & coral bleaching & come to your own conclusion. Just because you dont test for it doesnt mean your levels aren't low.

 

[spieszak]

Randy did an article on Iodine...
http://advancedaquarist.com/2003/3/chemistry
Its my personal opinion (you know what they say about opinions) that if you aren't getting it replenished by water changes, you aren't doing enough water changes.. that is unless you are growing LOTS or macro algea... but, it seems to be one of "those" subjects..

 

[NanaReefer]

Lol-those dang opinions are everywhere!!! You should hear the ones I'm getting about what's wrong with my Jeep-wow!!
I'll be sure to read Randy's article. One more of many so far

 

[mfinn]

Well I'm not real inclined to dose anything I cannot test for. RedSea has an iodine kit, may look into that.
You think at 5g bi-weekly my WC aren't enough to replace trace elements? My tank is all SPS/LPS.
About +- 47g total water volume.

Should be.