i see it on ebay for 100ml baggged for £9.70 posted,i take it the bags you put it in are cheap to buy?
scott
For £9.70 on Ebay you get 100ml in a Seachem Media Bag, the bag on its own sell for around £8
The benifit the bag gives is you can "recharge" the Purigen in the bag, if you use something else as a media bag (ie ends of stockings/tights) you will have to remove the media to put it in bleach to recharge it which is easy enough.
I have just found 500ML for £27 posted so regrettably I am going to pull out of this one, sorry if I have wasted anyones time