[jonny thompson]

Hi I’m having problems with my TDS reading going a bit higher, I’ve changed filters and resin, does water pressure cause this , as when I’ve got my usual amount of waste water coming out the hose, only a trickle of water is going through the resin and into the tank at a reading of 3 , my water pressure is low though

[G Griffin]

It could be that the water is from a different reservoir and has a higher reading going in. You could test that first. 
I've heard they do this during dry spells.

[P @ F]

^^^What eee said , me and my bruv used to live a mile apart my water was around 100 his was 50 !