It leaks from the side of the filter. There's a seam on the side of the filter and that's where the leak is coming from. If I can't return the filter I'll try to seal it with one of those sealants that are fish friendly.
@ Zags its pretty much brand new but the catch is that I bought it off eBay. I do have another one coming to me from the same seller that I bought before this one started leaking. I've asked if I could return that one in exchange for another one.
@ Jake thank you for the info. I'm not using duct tape though. Lol
I would replace all the top sealing rings first as it may be coming down from the top in one of the seams
If not then pond milliputt is great you can Seal the leak with the filter running and it sets hard as stone even on pipes with mains water pleasure to stuff every fish keep should have some it come in 2 parts you brake of as much as you need from both bits rub them together push into the place of the leak which it deals right away and it goes hard in 12 hours