If I am understanding how UV works. It will kill all bacteria, but the majority of good bacteria that are needed for the nitrogen cycle are not affect because they are on surfaces such as bioballs, in gravel and not free swimming, therefore not going thru UV rays? Would you avoid this type of filtration while trying to establish the bacteria for the nitrogen cycle?
Also, looking for one that will be powerful enough for a 55 gal tank. So, would it be your Aquatop PSE1? This is a mechanical filter as well as a UV & skimmer.
Lastly, this is for a freshwater tank. Is skimmer used solely for saltwater setups? Any use in freshwater?
Thanks for clarification.