New Live Rock Bleaching

[richnv]

I have recently upgraded to a 135 gallon tank from a 50 gallon tank. The new tank measures 72"LX18"WX24"D. Nitrite=0, Nitrate=20, Ammonia=0, PH=8. I have 2 Tank Raised Maroon Clownfish, 1 Tank Raised Bamggai Cardinalfish, 1 Tank Raised Splendins Psuedochromis, and 1 Cleaner Wrasse. I have about 60 lbs of corraline algae covered live rock fron the old aquarium. Currently I am using 1 175 watt metal halide along with about 200 watts of 50/50 standard flourescent lighting. I have added some new live rock and several days after adding the new rock, the green covering on top of the rock turned white (bleached), while the underside of the rock remained green. This happened to all the new live rock at the same time regardless of the specific day it was placed in the aquarium.My old live rock is fine with no bleaching and remains covered with corraline algae. The new live rock I curred myself and had gradually added about 50 lbs over two weeks when the bleaching occured. I had been using the metal halide only about 5 days when the bleaching occured. I have no corals at this point but would like to add some in the future. The bleaching appears to be rlated to light exposure, but I don't think my lighting level is too high. Is the bleaching something that I should be concerned about and what might be causing it?

Thanks,
Rich

 

[Fatal Morgana]

IME, bleaching of the coralline is due to salinity shock and light shock. It usually takes several days for the bleaching to be visible, since the color that responsible for the coraline algae does not "fade" instantly. If the condition of the tank is good, there is nothing to worry about. The dead coraline algae will be replaced by the strain/color that do well in your tank eventually.

If your old coralline algea is bleached, then you should be more careful about what you did.

 

[Fatal Morgana]

Oh, bTW, welcome to RDO!

 

[richnv]

Thanks, I will give it some time and see what happens.

Rich