Neil, >> In my 70g tank with only 2 40w bulbs, no CO2 and peat substrate, my chain swords are extemely dense; more dense than I prefer. Consequently, they *ARE* choking out other plants and have actually choked out each other. << Isn't it amazing, different people's experiences with the same plants in different tanks!<g> E-mail from: Karen Randall, 14-May-1995