I know this is an oldish thread-But I just couldn't help sharing! So I have many outdoor ponds and fish tanks, and my favorite thing to do is root cuttings in the hang on back filter!! You just stick the plant in, and it takes nutrients from the fish waste and they always do AMAZING!! I have one tank just full of minnows, and I just throw in random plant scaps into the tank its self, and it's a great "catchall" for cuttings I am not really that interested in growing but break off or are scraps from pruning. I have a HUGE tradescantia that started from a small cutting that has overtaken one tank, inside AND out!!!