Layer of Gunk?

[wataugachicken]

Thanks, that worked perfectly and pulled alot of the DOC's off and made the top much clearer and noticably better.

I'll have to take a look at the skimmers, are DOC's harmful? or do they just block light from entering the tank?

glad i could help.

 

[Subliminal]

First, when you do your water change, use a cup and just take the water off the top. No need for a syringe. Dirtiest water is almost always on top, anyhow.

Second, you should probably just up your flow a little bit. Add a powerhead or something. Agitate the surface a bit more.