Hello,
I have had the same corals, I bought, almost 5-10 years ago. Once I had purchased 1 SMALL xenia the size of your pinkey. This was purchased maybe 6-7 years ago. Over the course of a year after I had purchased it I saw that it grew like "weeds in your grass". Any open area that didn't have a coral of some sort on it got overtaken. We'll, roughly a year went by and I noticed what most everyone here has noticed. They shrink away but everything else thrives including all my hard corals and clams. I figured, hmmm, not a good match and chaulk it up to my fist major fatality (like losing your front lawn at this point). I checked everything and all was well and had no explanations.
About a month later I noticed a VERY tiny "smear" of what the xenia looks like when it spreads (without any branches or bumps, like a smear of gum). To make a long story worse, I saw the carpet of xenia take shape once again. Out of nowhere I was back to where I was when it was filling in all open areas.
I have witnessed this every year for some reason. In fact, it is starting right now. No worries though... My levels are perfect and all my other corals are still doing fine. You'll know when they are "thinning themselves out" because your skimmer will go into overdrive! I have yet to lose anything else to date but this oddity always happens on a yearly basis. My opinion is that the tank is taking care of itself. I wouldn't do anything out of the ordinary to make sure you don't mess with the balance in your tank.
The same philosophy holds when you see things "show up" out of no where. Things just seem to grow and you never bought them. Sure, there are things in the live rock etc., but doesn't expalin years and years later. I think that life will find a way and if we are taking care of our tanks to the best of our abilities and not cutting corners then we should look at these types of things as an accomplishment. I know death as an accomplishment sounds strange but think of nature and how it weeds things out.
To me, it simply says I'm doing it right and don't mess with it! In the next month or so I know from the past years experience that my xenia will be back. Gives a little time for everyone else to spread out and breathe a little. Hang in there and if your situation is like mine then they will be back.
For the hair algae and cyanobacteria (
red slime that is NOT algae) people. Fix your water, that is from phosphates. If you test your phosphates and they are good, change your light bulbs! There are more people out there not replacing their bulbs on a regular basis. They become "out of spectrum" and into the correct (bad) spectrum that all the hair algae and cyanobacteria thrive on.
My 2 cents...
Tattoo
