Hi, I am building a 5000 litre pond right now and purchased a fishmate 15000 filter. I noticed the hose tail connectors didn't come with any o-ring unlike my UV filter and pump and there does not seem to be any space to fit one either. When I plumbed it in and tightened it up it leaked badly on both the inlet and outlet. Even PVC plumbers tape around the collar and a jubilee clip for good measure hasn't stopped the leak completely. Is this a known issue with the Fishmate connectors and is there a way of getting a non leaky connection? Any tips or advice greatly appreciated!