Been looking round my case and just noticed that there is a fold in one of the pipes. Where the fan is at the floor of the case near the psu. The pump is right under the fan and so i was following the pipes and noticed that there is quite a fold in the pipe it would appear it must of been pressed against the fan and so its caused it to bend. But when i checked the pipe wasnt againt the fan but the bend is clearly visible. So this may been a problem causing water to slow down.
Will look in bios in the morning right now need to get some kip. Thanks for the help guys.