Hi, I have a Facelift Phoenix system and changed the filters and DI resin on Sunday and the TDS reading after the change was 001ppm which is OK to use. I have done a few cleans over the last couple of days. I also carried out a flush and a refill and now the TDS reading is showing 006ppm. As this was my first filter and resin change I only put in half of a 25 litre DI vessel worth of resin. Should I have filled it all the way up with resin. Any ideas please?