Do I need a Skimmer?

Depends. If it is a saltwater tank, then yes I would definetly use one. If this is a freshwater set up, then no a skimmer will not bre needed. Generally protien skimmers are mainly used in saltwater aquariums.

Marinemom
 
if this is a freshwater tank, protein skimmers will not work since the water doesn't have sufficient surface tension for foam fractionation to occur.
 
Surface skimmers are the only skimmers that work well with FW tanks. They polish the surface and keep dust from gathering at the top.

I use the Fluval skimmer add-on attached to my filter and it works better attached to the filter than my powerhead =)
 
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