Hi guys. I bought a complete waterfed pole trolley system from Pure Freedom back in the summer of 2008 including a DI vessel and RO unit. Up until now I have always had a reading of 00.0 with the TDS meter but in the last few days I have noticed that it has started to creep up to 0.01 so I'm guessing it is time to replace the resin. I have never done this before though so I'm unsure as to what I am doing. I have a few queries and any help would be appreciated.
1) I notice that there are several different size bags of resin available or at least there are from the Pure Freedom website which is where I would most likely be buying from. They sell a 25 litre, 5 litre and 1 litre bag. I'm thinking that just the 5 litre would be sufficient?
2) On the Pure Freedom website they also sell a filter cartridge complete with DI resin for quite a low price so could I just buy that instead and not bother with a bag?
3) If I did have to buy a bag how do you go about changing it? Is it simply a matter of emptying out any of the remaining old resin and then pouring in the new stuff?
4) Once I have changed over to new resin can I go back to purifying straight away?
Thanks for any help and sorry for all the questions.