Paticulate floating in tank

[digital-audiophile]

So I am starting to get a little annoyed. I always seem to have particulate floating in my tank, I am fairly sure they are not microbubles, as my skimmer is in my fist sump chamber and flows into a filtersock and then over/under the baffles. I do not seem to see the same "matter" floating in the sump, but in the main tank it just always seems to be there. I do have a sand bed and a very active sleeper goby that is always mucnhing on the sand but I don't think that would be the cause of it.

Any suggestions/advice?


Thanks!