My live plants aren't doing so well. I put the plants in about a week ago they are for warmer water tanks: getting ready for Discus. All my Nitrates etc are pretty normal and I put the required amount of plant food and lighting for 8-10 hours. I can't figure out why they seem to be dying. I am wondering if they need more that just gravel at the bottom of the tank? I can send pics if needed. Thanks. Tim