My Ocean Clear leaks... ALOT!!!! I replaced the O ring, replaced the lid and tightened the retaining ring with a rubber dead blow hammer. It still leaks!
I have not tried a Nuclear filter so I can't say it is any better... but I would definitely NOT recommend an Ocean Clear!
I gave up on large canister cartridge filters and went with a small Hayward DE pool filter. The Hayward is small as in for a small pool but a huge DE filter area for a aquarium. I love it... perfectly clear water!!!!