White blob - growing under Coralline? rock to rock?

[nancysnuwave.com]

Hi,

I'm new to aquaria, and have a 75 gallon S/W tank which I just bought
used( see http://www.nancysnuwave.com/aquarium/75gallon.html). With
it seems to have come some white blobby type growth which is spreading
from rock to rock. It seems to be pushing under some coralline algal
growth.

Here's a picture:

http://www.nancysnuwave.com/aquarium/slimy_stuff_disrupting_coralline.jpg

It reminds me of something I saw in a botany class once..

Any clues as to what it is and what I should do about it if it is
something 'out of control'?

Thanks!

[steve1s]

The pics a little fuzzy but it looks like a type of creeping sponge. Do you see anything in it that would resemble small holes like aerated bread and translucent? Or is it greyish, smooth and opeque?

Shouldn't really harm the coralline if a sponge but will slow it's growth rate. Extra water flow will slow it or force it to recede.

If it's greyish and opeque, it would be a type of competing coralline and will overtake the the colored coralline. The grey coralline does not like direct light so tipping it upward should allow the purple to gain ground again. Longer actinic periods will also help.

And
http://members.shaw.ca/steve-s/welcome.gif To Reeflounge.com

Cheers
Steve

[nancysnuwave.com]

Hi Steve,

Thanks for the suggestions and the help.. here's a shot of another piece. It looks more grey and is more exposed to the 50/50's and Metal Halide lamps (which I just started up yesterday). Perhaps it is the algum you mentioned (it seems quite thick - almost 1/4" or more).

BTW.. any ideas from anyone on how to get the Olympus D-380 to focus better for these shots?

Chris

[nancysnuwave.com]

one more thing. it doesn't seem to have any holes like bread.. just smooth, leather-like.

[tangwang]

I believe Steve is right, it does look like a type of creeping sponge. This type of sponge is usually removed from the rock during the curing process by the LR farmers or dealers. This is because most sponges generally dont last very long in closed systems, and present even more die off. I have seen some LR farmers leave these sponges alome though.