Brita system is a jug that has a fitting for a small cartridge, which you put your water in, and it flows through the cartidge. The idea is that you then use it for drinking and the kettle etc where you dont want lime scale. Have a look here:
http://www.brita.co.uk/action/products/Since brita, other companies have come up with their own versions, Kenwood, Morphy Richards etc. Bit cheaper. It was Kenwood cartidges I used.
The water through one filter isnt pure enough, as there is only a small amount of resin in 1 cartridge. (I tried it before)
I put all that resin in the coke bottle, (good point about the resin spilling out too- an old, but clean sock came to the rescue as a filter) I ended up dribbling it in the top, and syphoning it from the bottom. Was slow but okay. Have just done my windows with it, waiting for it to dry now.
I'm wondering if it is the proper type of resin needed, "strong acid" instead of "weak acid" resin that will only remove some dissolved solids.
Silly
[expensive, yes. But alternative is 25litres at ~£70 and is only to test my idea)