I just used cotton thread.
I thought that the riccia would attach itself to the wood so i used cotton since it eventually disolves away. Now that i know better I will be using some nylon thread/ fishing line when i take to out to trim.
Well the Hagen CO2 packet only lasted about 2 weeks. I just set it up with a new pack 2 days ago and nothing happened. Not one bubble? Container was rinsed well, luke warm water was added and nothing. Could it be the one way valve i have on the canister the might of sezied up?