I am sure i have read about these somewhere ,not sure if it was on this site so sorry if I am reapeating somthing.I have just bought a pack of these pills after seeing the ad in fwb,dropped one into a litre of water as instructions & waited,& waited & waited,nothing happened.It says in the ad effervescent rapidly dissolving,not mine,it just sat there on the bottom of the vase.just wondered if any of you guys use them & if so how do you get on with them do they fizzzzzz,have i got a bad box?