Black film in tank?

[njbluefish]

All,
I went on vacation and came back to find this black film on my LR and Sand. I scooped out what I can........and tried to remove it from the rock and dead coral. I just cant seem to get rid of it. I would like to know what it is and how to rid of this fast spreading stuff? Any thoughts

 

[imo]

Is it slimey? How long has the tank been setup? A lot of red slime can look nearly black in certain light. You probably had a red slime outbreak while you were gone.

 

[hairtrigger]

Yes, cyano bacteria, aka, red slime, can also be dark, dark green. Resembling black, but not quite.
Second Kipass's point. But I'd also check phosphate for the heck of it too. Cyano loves phosphate.
Do you use tap water? I'll bet your phosphates are too high if you do. Also, how long has the reef been established?

 

[njbluefish]

Thanks all for the posts........my tank has been up for about 9 months. I do not use tap water RO/DI from the LFS. There is some dark red but mostly real dark purple/black film with bubbles in some spots. The only chage I have made to my tank in the past few months is 3 Smartlights 65W for a total of 195W (50/50 bulbs). I only had 65w. before and wanted to start with some corals.....basic reef system. I have tried a Phosphoguard (pellets in a filter bag....I think that is the name) but it just seemed to slow the growth. I want to rid of this so called slime but do not know were to start.
Any additional thoughts or suggestions would be a great help.
BTW....my water is in great shape????? Go figure.......
Thanks,
Mike

 

[hairtrigger]

Yeah, certain spots usually means "dead areas." Eg... like Kip said... low circulation. Also, if you have a DSB, and that's where the spots are... check to see if you have a proficient clean-up crew. Sometimes too many nutrients build-up in the DSB, and that can surely lead to cyano.