When I bought these, they were super small. Since then, (two months later) I've had to trim them multiple times. They grow like crazy with the correct conditions! I didn't plant the hornwort, just attached it to a small piece of driftwood. No liquid fertilizer, nothing to help it grow except light for about 8 hours give or take, a day. It will grow up to ten feet, with waters 56-86 degrees farenheight. Really cool! It also helps to prevent algae more or less.