I've only had crypt melt occur with old tanks where I neglected the water changes. I've read that high nitrate levels may cause it. I've purchased 'new' crypts via mail order a number of times and never had any melt on me immediately. The melt occurs virtually over night. The plants look vigorous and happy one day and I turn on the lights to mostly mush the next. That's what I've been calling 'crypt melt'. I tend to use potting soil underlayers/fine gravel topping and never get around to doing things like fertilize. CO2 injection has never been a technique I've used. I do try to keep up with water changes though (weak grin). Betty Goetz - low light low tech plants! _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member