What is this vein-like thing(s)?

[oabda001]

Hey guys,

I'm fairly new to the hobby. I setup a 40 Breeder in April, and today I have a pair of cardinal fish, a pair of clowns, a cleaner shrimp, and a cleanup crew (small snails, emerald crabs). Everything looks happy and healthy. Zoanthids (only coral in there) look good as well, and new colonies are spreading on all the live-rock.

Here's the problem: holiday season is upon us, which means I'm working longer hours at my retail business, and I have a lot less time to stare at my tank and do regular water changes. My hob protein skimmer is doing a great job at keeping parameters at normal levels, and the canister filter is maintained/cleaned every 2 weeks or so.

Tl;dr: I came home last night to find this strange, vein-like, branchy, looking stuff spreading on the glass of my tank. There are about 5-8 of them spread out on all 4 walls. I only noticed them last night. They may have been there for a while.

Anyone have an idea of what it might be?

I'm new to this forum stuff, So I hope I'm posting in the right place.

Thank you!

 

[Salty1962]

It looks like algae.

 

[saltyfilmfolks]

I'd say tube worm or foraminifera.