There’s nothing inherently wrong with a canister filter, I ran one one my first reef tank. I also had high nutrients though. They’re not conducive to running low nutrient, SPS-friendly systems, because the waste they trap to be removed is still in the water system until you clean the mechanical filter media. In contrast, a skimmer holds the waste outside of the system until you empty the skimmate collection cup. So you have to be extremely diligent about cleaning any canister or HOB filter in a reef system, pretty much weekly, or your nutrients levels will be out of control. Which is why the biggest factor to consider when planning a canister or HOB system should be the time it takes to break it down and completely clean it, and most HOB filters are much faster to clean.