Okay, I'll post the magnesium article as well :biggrin:

http://www.advancedaquarist.com/issues/oct2003/chem.htm

I have not read in that article that low magnesium causes coral fading, though I might have missed it.

I'd get a magnifying glass and look for red bugs. My acros did that when afflicted with them.

:lol: :lol: :lol: :lol:

Whats happening with your Montipora species?


Wendell

Are the polyps extended or retracted most of the time? Is it affecting all your SPS? How often do you do water change? what percentage and what brand of salt? How is your skimmer doing?

How about increasing your MH photo Period. 1pm to 9pm is 8 hours. If you think about it most of the coral we have liver near the equator and has up to a 12 hr photo period

Just a thought

J

This problem is also effecting my montipora. They have all died as well. It was very noticeable on my digitata, they faded really quickly.

The polyps are extended on all sps, they appear to be healthy, albeit fading. I am using IO salt, and do a 30 gallon water change every 2 weeks.

I have a 40" becket skimmer (one of Dez's) that does a great job. I also use 100 micron filter socks on my 2 drain lines to my sump which pulls out most particulate. The water clarity is very good.

I reduced my lighting time after reading articles on RC on fadings sps. It has not helped the problem. I think I might go back to a longer MH lighting cycle.

Any more thoughts on this?

I don't think increasing his photoperiod would help since his corals are lightening, which is usually a sign of too much light or pests.

If it's occuring mostly on your montis, I think you have monti nudibranchs. Do a search on RC (when it's available) for 'nudibranch'. There are alot of threads which explain what it is and how to deal with them. There aren't that many treatments you can perform, it seems like only removing these little bastards manually is the way to get rid of them.

Red bugs don't normally go after montis, but mainly acros. So if your acros are spotting or receeding from the base up, you may want to take a magnifying glass and have a look.

Do red bugs effect acros only from the base up? In my case this is not happening. It is a fading issue on the entire colony and does not start at the base or tips.

I have not used a magnifying glass yet but I can't see any bugs or nudibranches with the naked eye.