Brown/Stringy Algae Problem... attaching to corals. What is it? What do I do?

[Dturner]

Hey guys,

My saltwater system has been running a little over a year now. I did upgrade to a new tank about 2 weeks ago and used new sand, but kept majority of the old water and used all of the old live rock. As of the past couple weeks I have been having a bit of a stringy brown algae problem... it seems to affect the corals mostly, it seems like it attaches to the corals and definitely seems to keep polyps from extending, some more than others. My leathers and softies seem to be the worst affected by it, my leathers haven't opened fully/happily in a while.

I did a 30% water change 2 days ago hoping to help it and I have also done a blackout for 2 days this past week. Since the blackout I have very slowly kicked my T5's back on, I ran 2 actinics for 2 days for about 4 hours a day, I have just started running 3 additional actinics plus 1 12k daylight bulb as of today.

My parameters:
PH: 8.2
Phosphates <0.03
Ammonia & Nitrites = 0
Nitrates - Undetectable
Calcium 400
Alkalinity 9
Magnesium 1100ish (working on bringing this up)


I am running a GFO reactor with high capacity gfo with a BRS reactor. I have a 250 gallon rated reef octopus protein skimmer. I have 2 filter socks catching junk from my overflow. If I forgot any params, let me know and I will post them. Pic posted below to show what I am dealing with.

Please help me solve this problem. I think it may be affecting the well-being of my corals and I don't think it's diatoms.

 

[little_fish]

Ya, that isnt diatoms. How fast is it spreading? If its spreading like wildfire, it might be dinos, which are really hard to deal with.

Otherwise, i would suggest doing more water changes in the mean time, sucking out all that you can. This is probably fueled by the move, because there will be some stuff stirred up from moving the rocks. Hopefully it will burn itself out fast.

 

[Dturner]

I think it is dino... WHY?!?!? Guess I have my work cut out for me over the next few weeks. Damnit.

 

[Dturner]

I have 3 clams and a bunch of SPS and LPS and soft corals... would it be bad if I blacked out my tank for a week? During the 2 days that I did the black out it seemed to help a lot.

 

[little_fish]

they will be fine, just re-acclimate

 

[Bifferwine]

I agree -- it's probably dinoflagellates. Especially if you see snot-like strings with bubbles. A black out is the most effective way of getting rid of them.