Thanks to all you guys for your advice. Done all you asked and tds after production for 1 hour (before attaching di) was 26. Put into Di and now getting 000 which is obviously ideal. Take on board what you all say about booster pump as it has taken 36 hours to produce 300 litres from a 200gpd system, is this normal??? appreciate booster pump will take a lot less time to fill and will bring tds down slightly. Been a right pain actually as left it all today to produce and gone in tonight to check to see how it was all going and floor in shed was soaking and appears that the tap from water butts bought from bandq has been letting by so am not a happy bunny!!!! tightened it all up and emptied it into my containers for my trolley and now going for it again!! so wish me luck haha. aLL YOUR HELP GUYS IS GREAT THANKS VERY MUCH