live rock bleaching

jehudson · #1 09/08/2007, 11:53 PM

I've got a 90 gal tank, live sand, approx 80 lbs. live rock. wet dry filtration w/in-sump protein skimmer. some of my rock is losing it's purple color and turning white. White areas were covered in a blue-green color but that has gone away (white areas seem to be growing still). I know it's not good and don't know what to do about it ... any ideas?
ph 7.8 (don't know why it's dropping)
Nitrates 20 ppm
Nitrite 0
ammonia 0
brown and green algea are not a problem.
temp 75 F

rcerulli · #2 09/08/2007, 11:55 PM

do you check for calcium and alkalinity? Sounds like they may be way off balance (hence the thriving algae as well)

coast2coast7390 · #3 09/09/2007, 12:06 AM

it could be lighting also

jehudson · #4 09/09/2007, 12:08 AM

calcium is 430 ppm ... that's pretty stable, but the ph drops and I have to continue adding a ph buffer to get it back up to 8.3 again. I have a feeling that has something to do with my problem, but I'm not sure what to do about it. Do you know if those bleached areas will be able to re-grow that purple algea?

Mavrk · #5 09/09/2007, 12:23 AM

pH buffer will throw off your alkalinity I believe, and this could be the source of the problem.

deklin · #6 09/09/2007, 12:25 AM

I would suspect lighting first. Did you recently change to a new lighting setup, change your bulbs to much brighter ones or reposition your rock to put the rocks that are now bleaching into high light areas?

I've seen many people bleach and slowly loose coraline algae of rocks in the upper area of the tank after a lighting upgrade. There are different kinds of coraline and many kinds that thrive under low to moderate lighting will die under high lighting.

RBCJay · #7 09/09/2007, 12:33 AM

It does sound like lighting, have you changed bulbs or type of lighting recently?
Also, yes you will regrow the coralline in time when the issue that is causing the bleaching is resolved.
Jay

jehudson · #8 09/09/2007, 12:34 AM

lighting is the single tube that came with the tank ... I did put approx 40 lbs of new rock about 3 weeks ago.

jehudson · #9 09/09/2007, 12:37 AM

Quote:

Originally posted by RBCJay
It does sound like lighting, have you changed bulbs or type of lighting recently?
Also, yes you will regrow the coralline in time when the issue that is causing the bleaching is resolved.
Jay

that's good to hear about the coralline ... I've been saving my pennies for a long time for all that rock and was concerned I was about to have 80+ lbs of worthless decoration pretty soon.

.::Jun77::. · #10 09/09/2007, 01:16 AM

Quote:

Originally posted by jehudson
lighting is the single tube that came with the tank ... I did put approx 40 lbs of new rock about 3 weeks ago.

you just placed a new rock to your tank. it will grow up soon! happened to me too, bought LR online, bleached, then came back to life after a month. peace!

jehudson · #11 09/09/2007, 01:20 AM

thanks folks ... my hope is restored

... goodnight

SaltyDr · #12 09/09/2007, 01:23 AM

It's very normal for the coralline to bleach somewhat after being placed in our tank. With good parameters and lighting, it will grow, and grow and grow. What exactly is the lighting? If it's a single NO fluorescent, it may not be enough light and the coralline is dying due to lack of lighting. No matter what, the rock will still be "live" which is the bacteria contained in and on the rock. Oh yeah, and [welcome]