i was reading backposts because i noticed my tds out of the ro had gone up to 100 when it used to be around 6, panicking thinking about buying membranes and filters at around £100 unitil i read someone on here said check the waste pipe is not obstructed.
well low and behold the drain cover holding it in place was obstructing it, ik moved the waste pipe and there we go tds at 6 again :-)
cant remember who posted this great advice so thankyou masked stranger had it not been for this forum i would have spent some of my hard earned window cleaning tokens