Protein Skimmer

I would keep the filter. If you want to save money on upkeep just get an external filter. Either way I would keep a filter.

 

for fresh water......it's not needed, for salt a filter keeps the ammonia nitrates etc low.. i would invest in both a good protein skimmer and a good canister filter

 

i use neither

a skimmer is used to remove protien in water if you have live rock then this is your filter unless you want rid of all the small particles in the water then use filter floss and change it weekly

skimmer does not affect ammonia or nitrite in the tank it only affect the build up of nitrate by removing the protein befor it is converted to nitrate

filters like externals are nitrate factories and can drive up nutrient levels if not cleaned out weekly

 

There is 2 points to be made of this quote:

1. Protein Skimmers DO affect ammonia levels. As you said in the quote, skimmers remove proteins from the water, some of this protein becomes ammonia by conversion, the same as nitrite and nitrate. The less nutrients in the water column, the less ammonia created by conversion and the less of all the associated per the nytrogen Cycle.
2. You do not need to clean your external filters weekly. The only reason why you create higher levels of nitrate vs ammonia and nitrite is because of the cheer concentration of aerobic bacteria that causes the n02 and nh3 to be converted to n03. There is not nearly as much anaerobic bacteria in our closed systems to deal with the great ammounts of nitrate thus the accumulation of such, and the need of water changes to dissipate them from water column. It is the Un-balance of aerobic vs anaerobic bacteria that creates the excess n03 in our systems, and this is fueled by nutrients derived from waste (food/feces/deaths, ect)

 

ditch the canister filter, get a good protein skimmer with that money and i would set up a refugium (it doesn't have to be fancy) i have always used diy ones.