Let's talk about bio load.

[mikellini]

Originally Posted by sphelps

Over-skimming has nothing to do with removing beneficial bacteria, while such bacteria exists in the water column the amount of it compared to what attaches to surfaces in basically zero. Skimming removes bacteria about as effectively as water changes.

This isn't exactly true... For example, systems in which organic carbon is dosed remove a lot of bacteria via foam fractionation (skimming). This is actually the primary way in which such systems control phosphates; by removing the bacteria that bind/use/consume them from the aquarium. Also why skimmate colour changes significantly when dosing carbon (ethanol, vinegar etc). Zeovit systems also remove a substantial amount of bacteria by skimming; when the 'mulm' (basically bacterial biomass) is shaken and released, whatever isn't immediately eaten or otherwise used by the inhabitants is skimmed out.