I’ve ran just about every skimmer brand on the market.
Recently I ran the nyos 220 and the reef octopus 200 elite on my reefer 525. Both are excellent skimmers.
reef octopus was the best of the 2 as far as price, quality, performance and extras.... they were both dead silent.
I loved the nyos220 but it was a little tricky to service. The elite 200 has a built in float switch which worked flawlessly. It also pulled the most skimmate comparatively.
nothing compares to my old school euroreef rs250 with eheim 1262 though... it’s a beast but I wouldn’t run it in my living room