It works great for my 75 I have a heavy bio load. I like the dc pump on it as well. I’ve never had any issues besides getting the pump primed the first time was a little tricky. Right now I have it draining into a 5 gal bucket along with the waste from my Mastertronic and haven’t had any issues with it at all. I’d recommend it over the k3-200 specially since the 200 it’s a little undersized.How does it work for you on your 75 Gallon. I have a heavy bio load IM SR-80 and I was between the K3-250 and the K3-200, the K3 heavy says 60 gallons and the 250 says 140 gallons. I would be upgrading from Aquamaxx 1.5 HOB, which I feel has horrible air suction. thank you