Our new 90X45X45 aquarium arrived yesterday. Our first order of business is to decide whether to go with stones or gravel on the bottom. We want to have lots of plants and we are planning to go freshwater. Any suggestions as to what we should do -- soil or stones? Also, plants here in Japan cost a fortune. Any suggestions as to whether we should get a Co2 device for the plants -- and if so -- what kind to get. Then what plants are best???