[C & S]

A bit of help please gents,
My 350 ro is creeping up. To 6.

Do I need to change filters in it? (350gdp) if so can anybody post me in right direction.

And secondly, I have DI vessel, is their any way adaptor to put ro tubing (the really small one) into a bigger 8mm one so I can put it through my di vessel before it goes into tank?..

[p1w1]

By filters do you mean membranes? if so then i wouldn't say so (you will be fine using your water at 6ppm but good practice to get it sorted out back to 0). When was the last time you changed your pre filters and membranes? As for DI vessel yes you can just find out what size thread your DI vessel is and get the relevant adapter/ reducer to fit (350 gpd will be 1/4 inch tubing i think. Your DI vessel once you get that connected up and filled with resin that will bring your tds back to 0.
Something like this type of fitting (but get the DI vessel thread size first..https://www.amazon.co.uk/GUEST-Speed-Converter-Reducer-Connector/dp/B0041T0EPW if your DI vessel is a female thread you will need a reducer as well.