Can Anybody Identify This Algae?

[drstevemiller]

Hey all
This algae has been persistant for a few months despite monthly 25% H2O changes and manual removal. Its starting to know grow on/kill my SPS.
The tank:
75 gallon with 30 gallon sump
RO/DI water
50+ lbs of live rock
SOS, LPS, soft, and polyp corals
running GFO, carbon, and skimmer
Cleanup crew is 4 sally lightfoots and 2 turbo snails
One 12" clam in tank with 2 ornamental shrimp
ONLY 2 FISH - pseudochromis and medium purple tang
Nitrate, Nitrite, Ammonia, Silicate, and Phosphate levels negative
Dosing with 2 part C Balance
SG 1.024-1.025
Temp 76-78 using a digital Arctica Chiller
2-250 metal halides for 8 hrs and 2-4' VHO Actinics for 11 hours
Any help would be much appreciated. Thanks!!!!

 

[MBVette]

looks like that might be bubble algae I see in there.

 

[drstevemiller]

more pics....

 

[Gary Majchrzak]

possibly dinos? (can't tell from here).

what's your aquarium's pH?

do you use kalkwasser for evap topoff?

 

[drstevemiller]

pH is 8.3-8.4
I top off with RO/DI - I don't use kalkwasser

 

[Gary Majchrzak]

compare online pix of valonia (bubble algae) and dinoflagellates

compare online pix of valonia (bubble algae) and dinoflagellates

the way it's "dripping upwards" indicates dinos to me

 

[Ohiomom]

I had those types of bubbles when I had a battle with cyano too..so that could be a possibility also..