coldcazzie
Ice Queen
It's looking really good Tom although at the leech!
I think it'd probably be fine with a filter, especially something like a hamburg mattenfilter. The key really is in the large surface area and having plenty of plants and leaflitter to be broken down - and not cleaning it! Having said that, if you plant heavily enough and the plants are growing well then I don't see any need for a filter other than water movement if desired.