I have Gardiner aquatec pump but last few weeks has an annoying habit of slowing down pressure so have to turn up controller blow it out then turn down to 35-40 my normal rate, anyway few jobs later it does it again? I do have analogue controller so can't regulate pressure, do you think that could be problem? It's only a year old pump. If I have to go digital I will but have found them problematic in the past & find analogue less likely to break!