SPS question?

[Frost3839]

I understand when my sps bleach from the topto the bottom. There is a list of reason. But what does it mean when it is the other way around? Bleaching from the bottom to the top? I would think it is because the bottom in no longer reciving light due to the top growing and blocking the light from the bottom. But someone was explainging to me it maybe someone else. But it was a short convo and got cut off. Anyone care to explain?

 

[MarcWeaver]

It could be a pest, such as acro-eating flatworms, which do not like light and will usually start eating at the bottom and undersides of the lower branches. I have also heard theories that excess phosphates can wick from the rock the coral is glued to and destroy the colony from the bottom-up. I have several medium-sized colonies and they are all bleached at the bottom and have seen maricultured colonies right from the ocean that are as well. I think it's mostly from lack of light like you said.

 

[Frost3839]

Thanks! I understand there is a few ways to get rid of worms if that ois the issue. Such as wrasses and etc. But do you have any idea if iodine dip would kill them?

 

[MarcWeaver]

Here is lots of info on acro-eating flatworms. I've never tried, but the article says iodine will work: Wrasses will not eliminate the problem, but can help control it to some extent. Almost all fish will eat flatworms blown off the coral with a turkey baster in the tank.

http://reefkeeping.com/issues/2007-09/mc/index.php

I have personally used Bayer Insect Killer to treat a few colonies. It stuns them enough that they can easily be blown off, but it does not always kill them. You have to take the coral out of the tank, dip, and rinse well in saltwater before you put the coral back in the tank. Throw the rinse water out. Shrimp are very sensitive to the ingredients in this. There is a great, long thread on bayer insect killer here.

http://www.reefcentral.com/forums/showthread.php?t=1965880

 

[Frost3839]

Oh ok! Thanks for the links and info! I will strat reading the threads now and see what I learn!

 

[Reef Bass]

What you describe as "bleaching from bottom to top" may be tissue necrosis and not bleaching. Bleached coral tissue has expelled its resident zooxanthellae, but is still alive. STN and RTN often creep up from the bottom, and there is no live tissue there. One of the triggers of bleaching is sudden exposure to too much light, which is more likely to occur in the upper part of the coral than in lower shady areas. That suggests to me that your "low bleaching" is necrosis.

Yes, the upper branches of larger colonies can shade lower branches which can in turn can experience pigment and tissue issues as a result, particularly on the undersides of the branches.

And as already mentioned aefw love shady undersides.

 

[Frost3839]

Thanks!!! I believe it is necrosis as well. I did more reading on it after reading your post! I called it bleaching cause I didnt know a better term to describe it. Thanks again! I appericate the help

 

[MarcWeaver]

Good luck !! Some of my coral colonies still have STN at the bottom which stopped spreading but the coral will not grow back over those areas. Growth is fine at the top. Sometimes it cannot be explained, there are too many unknowns. There are other acros encrusting on the same rock.

 

[Frost3839]

Ya Ill need the luck lol. Thanks... I am trying iodine dip tonight to see if it helps stop it from getting any worse.

 

[reeferlover]

if i see STN or RTN on any of my sps i pull them. If you have another tank you can move them but i rarely ever see them recover. you can try frags as far away as poss but i just throw them out

 

[xenon]

When I see STN from the base of my corals, 9 times out of 10 its my alk swinging.

 

[MarcWeaver]

That makes sense in my case because I went from 8.5 to 7dkH in a few days. My dosing pump malfunctioned. That's around the time it started. I went back up to 8.5 over the course of 10 days and stopped but has not regrown back yet. Thanks.