I'm planing on getting my first monitor and was thinking about getting a pair of timor monitor. i have a custom made 4'x2'x2' cage for them. The site that I'm getting them from are selling them CB between the size of 12" and 14". I have bin doing my research for about 2 months. I've read to use a mix of play sand and topsoil is this a good substrate or should i go with zoo med excavator clay burrowing substrate. If the sand mix with top soil works good I'll go with that i would also like to know if they do good in pairs. I am not planing on holding them i respect my reptiles space and know timor or monitors at that don't like to be handled.