[The old man]

My experience with hornwort has been good and bad. When I first put hornwort in my tank about a year ago it was soft and grew like a weed. I was dumping the excess in my goldfish pond and was quite happy. Kept the algae at bay and seemed to be absorbing excess nitrates.
About two months ago it begin to get very brittle and stopped growing much at all. I took some of the best looking pieces trimmed it to small end pieces and introduced it to a new tank I was using to put some baby swordtails in. The new end pieces grew like weeds again and the stems stayed soft. Seems like it likes new tanks very well. It is keeping the baby tank clear and it sits in a window as it does my pond.