Bleached Coraline

[ColinD]

So came home from work last night to find the majority of my coraline bleached out? It was looking okay this morning, I will admit that I had missed a weekly water change last week and when I tested params Kh was 8 but Cal was over 580 (I stopped adding drops at 29 on my API test kit), and SG was 1.028.

Not sure whats going on here, just did a water change, SPS look fine, good colour and polyp extension, but the tank definitely looks strange without coraline.

Colin :ohwell:

[christyf5]

check your magnesium levels, I'm pretty sure thats what did mine in a couple years ago. I've currently got mine sky high and I've got coralline growing again.:biggrin:

Note: "sky high" not recommended, go for about 1350ppm or so :wink:

[Myka]

What else is in the tank? Sudden bleaching would make me think temperature, but you could rule that out if there are other inhabitants that aren't affected. Slowly add more RO water to your tank to bring your sg back down to 1.025-6. Are you usign a refractometer or hydrometer? If you use a hydrometer, it likely is not accurate. Take it to LFS for them to compare to refractometer or calibrate it yourself: http://reefkeeping.com/issues/2004-06/rhf/index.php

[ColinD]

test with refractometer, with water change I was able to get it back to 1.026.

temp is a pretty constant 79.5 - 80.1

Magnesium is 1400

only other thing I've done out of the ordinary was to switch bottled RO water, noticed that the new water I'm using lists Demineralized water and ozone as ingredients, where as the water I was using before said it was 'natural spring water filtered by Reverse Osmosis'. Both have a TDS of 4ppm but wonder what effect, if any, the addition of ozone would have.

Colin