Hi Dave , welcome , i have just gone to wfp myself , the first thing i would do in your shoes is find out the TDS reading of the water you will be using , you will be able to come to your best option from that , my TDS is 100 and i only use DI this means that 1 bag of resin will treat 5000 L of water {roughly} .
If i use 250 L per day , its about 1 bag a month , some will say thats too much money , but i have thought about the RO and it wouldnt really benefit me at the mo cos im on a water meter , by the time an RO has drained off the waste , i would be paying as much for my water charges as i am currently spending on resin .
At the end of the day , what you need to look at is things like i have before you spend your money , if your not on a meter then RO is the best way to go , it will save you loads on resin , you will need to buy resin still , but nowhere near as much as with DI only .
Hope this helps , im sure you will get lots of help from others on this one
Cheers Rich P @ F
