Pet Forum / Aquaria / Marine Reef / May 2004

Hi guys.  I have a 15 gallon refugium piped into my 55 gallon FOWLR tank.  I
also have a 30 gallon sump.  The refugium is supplied from the sump thru a
powerhead.  I've had the refugium setup for about 4 months and about 2 weeks
ago piped it into my main system.  I have several macros and about 5 lbs
live rock in it.  Prior to piping in the refugium my nitrates were off the
chart, around 100ppm.  After about 2 weeks they have dropped to about 40ppm
which I am very happy with.

My question is, in the refugium I have seen a growth of a thin purple film
over the entire live rock.  It breaks up very easily with a spoon or finger.
What is this stuff?  I'm wondering if my flowrate is too low or should I
just let it grow?  I have my refugium lit 24/7 with 45W (15daylight,
15actinic, 15 6500k).

Thanks in advance.

Jim