I have commented several times on the advantages of a stream for filtering. I have a 25 foot stream with lots of plants including hosta and sweet flag. I really like the sweet flag but it can really get out of hand. I guess I hadn't removed and reset a couple of clumps for two years. It wore me out to pull it out. I have rocks in the stream and the root masses get under and over them and anchor themselves in. They also attach to the liner. These root masses ended up being three or four foot clumps of solid fine root mat. Absolutely great filtering material.

One of the clumps included an equally huge hosta section that was, like the sweet flag, directly in the stream. This certainly shows that hosta can grow superbly directly in the water instead of in a partially submerged pot.

One of my clumps was in my small (mini-me) skippy filter. It had completely taken over the entire 20 gallon garbage can. I guess my skippy must have been working after all because it was a solid mat. I have commented before that I thought the stream was doing most of the filtering. Kind of tore up my skippy plastic bottom support to get it out. Fortunately I didn't break any plumbing. I made it so some parts could be separated to aid attachment and cleaning cycles. This was only my second removal in 6 years.

Perhaps if you are further north, sweet flag (and hosta) won't grow so rapidly, but if you have listened to me in the past and gotten some sweet flag, you might want to get out there before it eats your pond or stream.