Cobwebs?? What's this stuff, is it bad?

[Coluber42]

Today I got to work and saw that my tank has what looks like cobwebs strung from the rock and macroalgae on one side to the wall of the tank on the other, and filaments running up and down various other places. It wasn't there yesterday, or at least, it wasn't visible. I haven't heard to expect anything that looks like this; is it bad? Is it good? Do I need to change the light level? Should I just leave everything alone and quit worrying?
I'll try to post a picture; it's hard to actually get a good picture of.


Setup:
My tank has been set up for only a week or so, and has macroalgae and one of Mustafa's moss balls, but no critters yet. The only reason I have to think something might be amiss was that before I set it up with actual brackish water, I'd left everything to soak in plain distilled water for a week or so. When I came back, there was a definite smell of decaying shellfish. I have some shells in there that came from the dollar store, as did the sand and stones. I rinsed everything well in distilled water again, and then set it all up "for real" with brackish water (Instant Ocean at half strength, plus distilled water). There hasn't been a smell since, but that doesn't mean there aren't still bits of decaying gastropod in there somewhere.
I've been leaving the tank light on 24/7, but at the moment I just have a sort of makeshift lid that is translucent rather than transparent, so it's less light than it would get otherwise (and I haven't brought in a timer yet).

[Ace]

Please, submit a photo.

[Coluber42]

There's more of it, that's just the only chunk big enough for the (cell phone) camera to auto focus on. It really looks like dust bunnies in the corner or something.

[Ace]

It sure does look like some rolled spider web. I would be pretty mystified by it too. However, I wouldn't be too worried. It's probably nothing to get worked-up over.

Alright everybody, thoughts?

[JennyPenny]

Your post reminded me of another on this site, so I did a search. Take a look at this thread:
viewtopic.php?f=16&t=5874&p=38735&hilit=Cobwebs#p38735
Another person had the same issue. I don't know how she resolved it, but she speculated it was a vermetid snail, which is known for making these "cobwebs" underwater to catch food. It's like a fishing net. I read they are harmless, but I don't think I would want them with my shrimps.
If this is what is in your tank, I would be very curious to find out how it got there! Did you use ocean water when you set this up?

[Coluber42]

JennyPenny, thanks for posting that other thread. Those cobwebs do look just like mine, so I'm reassured that it sounds like they are probably not a threat.

I didn't use ocean water. I used a piece of lava rock ordered from Amazon (but sold for aquariums), with some sand and shells and rocks from a craft store. There was something in some part of that stuff that smelled after soaking in (fresh, un-salted) distilled water for a week, and I assumed it was from bits left in the shells. I dumped that water out when I mixed up the brackish water and set everything up. Then I added one of Mustafa's moss balls and a chunk of his macroalgae.

As of Friday, the cobwebs had broken/fallen into a couple of bigger chunks, plus some cobwebby stuff still going across the lava rock. The tank is at work, so I guess I'll see what they look like on Monday. I have snails on the way now, so hopefully they will eat it and not get snagged by it.

[Stalker]

Sometimes I have the same in freshwater... Still dont know what is it but probably bacteria since I cant see any structure on microscope.

[Coluber42]

So.... as far as anyone knows, it is unsightly at worst, but won't hurt anything otherwise and isn't an indication of a disastrous water quality issue, correct? Is it going to keep growing and take over? I could get rid of the most visible filaments of it with a chopstick, but that obviously wouldn't eradicate it from the tank. Should I bother? Will something else keep it in check eventually?

At this point I have snails and macroalgae in my tank and there's a fair amount of brown algae on all the light-colored surfaces. The biofilm on the surface is definitely greenish. Am I ready for shrimp, or should I wait until until I see more green algae? Assuming the cobwebby stuff isn't a latent shrimp-killing monster, I mean.

[Varanus]

Mustafa seems confident that visible algae = the tank is ready for shrimp. You could always get an ammonia test done to be safe if you want.

[Coluber42]

I guess I was slightly unclear on whether I should wait for green algae to be more apparent, or whether brown is good enough. And want to be sure the cobwebs aren't toxic or something.

Mustafa seems confident that visible algae = the tank is ready for shrimp. You could always get an ammonia test done to be safe if you want.

Varanus - off topic, but I had to ask - do you keep monitors? Only curious because of your username.

[Varanus]

Varanus - off topic, but I had to ask - do you keep monitors? Only curious because of your username.

I love monitor lizards and think Varanus sounds cool (hence the user name), but properly keeping and feeding them is well beyond my abilities/living space unfortunately. I do have a trio of awesome snakes though (western hognose, california king, and centralian python).

[Coluber42]

Good choice then - I agree, monitors are awesome, but I don't think I'd take on the task of caring for one!
I don't keep any colubrids, either, despite my username. I had a corn snake that died last year after 19 years, just have a ball python now. But the spouse has been dropping hognose and occasional garter hints lately... not sure if the hints are real or just talk, we'll see.

These teeny tiny snails are totally my first pet that isn't a snake, LOL.

[Mustafa]

I guess I was slightly unclear on whether I should wait for green algae to be more apparent, or whether brown is good enough. And want to be sure the cobwebs aren't toxic or something.

Brown algae is good enough. Sometimes brown appears first, sometimes green. Doesn't matter. As for the webby stuff...it's most like bacteria, and it will disappear very soon. Happens sometimes.