I just acquired three large specimens of Trapa natans, from one of our better shops in the twin city area. I have placed them in a 3/4 full 75gal, full covers, to hold the humidity, a powerhead to help increase the humidity and four 4' full spectrum tubes(48"). I am presently using R.O. water with trace elements replaced as I saw fit. Has anyone any further thoughts as to what other things might help them to reproduce? Karl R. Schoeler