Coralline Algea fading away. Cause?

For the past couple of months my coralline algea has been steadily growing. I've been using PurpleUp and it was starting to cover all of my rocks and I was starting to get some dime sized pieces on my glass.

BUT, for the past two weeks it as been quickly fading away. The fading away went about 10x's as fast as the growing part.

Here are the only things I can think of that may or maynot have happened within that time period:

1) Breakout of GHA, which I have since gotten under control
2) Elevated Phospates(2.0)/Nitates(40), which lasted about 2 days now they are at .02/10
3) Switched lighting from one single PC to 2x54 T5s
4) PH has been a steady 7.9 and I dosed with Sea-Lab No. 14 to raise the PH back up to 8.3, but have yet to be successful

So which one is the bigger problem? Or could you please troubleshoot some other ideas that may have caused this.....any answers would be good just tell me what to look for.

 

There are many factors of this. What are your tank inhabitants? Urchins will mow through coralline. I had a GHA breakout a year and a half ago, and wasn't affected.

 

I knew there were many factors, im basically trying to troubleshoot this problem right now:

I do have an urchin (about the size of a golfball), but it's been in the tank for a very long time even while the coraline was growing. Do you think the urchin is treating the coralline like I treat my yard? Let it grow out of control then mow it down.

So the GHA doesnt choke out the coralline, good to know that wasnt the cause.

 

It's quite possible. I've watched my emerald aggressively pick at it on occasion. Quick or extreme param changes can be a problem as well. I manually ad a 2 part buffer/ calc solution daily. If I o.d on one or the other, my coralline will fade or become patchy for a day or 2. Since I'm adding manually, I do it at the same time everyday and very slowly. Stable params are an important factor. IMHO, the purple up is unnecessary if your mag and calc levels are within proper ranges.

 

the change in your coraline is from the change in lights. it is all changing at the same time because their photosystems are shifting to accommodate for this new spectrum. with PC lighting i suspect it was very deep purple... no expect it to be a bit lighter purple.

 

Good point Dingo

 

I test calc and mag with API and Salifert tests, both are in good ranges, so I'll finish out this bottle of PurpleUp and not purchase again. Thanks. There was a large swing in Nitrates for a day or two. From about 10ppm to about 40ppm, but I did a water change and its now back to 10ppm, which is normal for my tank.

 

Makes sense. So it will bounce back again once it gets used to the lights?

 

+1

And the winner is.... 3) Switched lighting from one single PC to 2x54 T5s and caused it to bleach! keep you other parameters in check and it will grow back quickly as it adjusts to the new lights.

 

yes... you will have partial die-off until they realize which photosystem is more efficient for the new spectrum.
it can take a few days or a few months but they will all shift color and still live... just have patience