So I got a aquaC remora skimmer and its been running on my 20 gallon for a few weeks... My skim is still almost water. Its raised all the way up to hopefully get dry foam but no luck... it fills with basically water after 3 days.... Any reason why this is? Do I mess with my tank too much so the oils from my skin, the food I add make the skimmer not work as well?... I think I've read this before in the manual.