I'm going to convert my 12 gallon eclipse to a shell dwellers (N. Multis) tank in a few months. I was wondering besides sand, and shells what else is a nessecity? Don't think I'll add any plants, but, wondered if I should be starting some sort of back ground now, over just my black garbage back, so they feel more comfortable. Should I be making rock sculptures to em to hide in, or is just shells and sand enough? Also, is there anything I need to add to the water? My tap water is naturally has a ph of about 8-8.2 and is incredible hard. TIA...