^^^^i agree it grows FAST but with regular tirmings it can be kept under control!!!! i just threw out 2-3 quart sized bags FULL of hornwort that was in one of my 10gals. and i trimmed them within a couple days!!!!!
Good luck!!!
EDIT: now i just got a 5.5gal. fry tank and i wish i would have kept some of the hornwort but i will have more in a couple days!!!!!