Sand bed ?

[Mil26]

What is this in my sand bed it's clear but moving like a clear worm leaving a trail

 

[KJ]

Bacteria start working in you sand bed.

 

[Mil26]

I was thinking that also but rlly I mean that's cool but what do they do eat my nitrates or what haha?

 

[KJ]

Yes eat you nitrates and keep tank more stable sorry for my English.KJ

 

[KJ]

Lets Talk Substrates for the Marine Aquarium this my help more.

 

[cloak]

It's probably just the trail left behind by some sort of worm or pod. No worries.

http://reefkeeping.com/issues/2002-03/rs/index.htm