Vegatable filter

[mort]

I'm rejuvenating my pond at the moment and have an old water fall which i'm wanting to change into more filtration because some of the fish are getting larger and messier. I've always split the flow from the filter so half went straight down the waterfall and half into a upper wildlife pond before it returned. So now i'm extending the wildlife pond with another small upper pond and stripping the waterfall with the plan of making it a vegetable filter. So my question is which species are best for it? Its 6x2ft ish and I can dig down as deep as it needs to be. I have plenty of iris which will go in there and a couple of variegated rush but is there anything better?

 

[foxfish]

Water Cress, it needs sun & warmth to really get going but is very fast growing and has always been my choice for vegetable filters.

 

[mort]

Thanks, must admit I did forget watercress when I wrote above. I had it in the pond last year and it went mental and grew several feet high. I'll see if I have any left or start some more.