I was thinking Hydrocotyle tripartita but apparently it likes warmer water. I does get cold in out house sometimes when the heating is off in the winter, like below 18c. Could give it a go and see.
I thought maybe riccia fluitains tied to the wood and maybe something else in the back right hand corner but I'm not sure yet.
Last edited by javajive1981; 12-20-2014 at 06:23 PM.