i recommend getting a kitty litter scoop and using it to comb the sand. it makes the sand last longer between change outs (and if you have yours in a seventy-something gallon tank like my malis, this can be a very good thing). i wouldn't recommend the vitamin sand. pool filter sand works really well, has almost no impurities of any kind (at least i have never found any). it's a little more expensive than play sand but lindsay pike recommended it to us and we have had no problems with it. of course, it gets all over the food but none of the uros seems to be having any impaction problems.
as far as a new playmate, the sooner the better. most uros are more accepting as juveniles to new playmates, make sure they are pretty comparable in size. be sure to take the other uro out of the tank, clean out the sand, maybe move some furniture, then put them both in at the same time so they start on equal ground (you don't necessarily have to do this, but with males it can help with territoriality). i recommend getting an opposite sex buddy too. hope this helped.
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1.2 Uromastyx Maliensis (Ricky, Quinn, Anna)
1.0 Varanus Timorensis (Zealot)
1.1 Varanus Acanthurus (Eddie, Roxie)
0.0.2 Uromastyx Aegypticus (Kronk, Yzma)
0.0.2 Ceratophrys Ornata (Mojo, Jabba)
0.1 Geochelone Carbonaria (Turtle)
Emily
www.egomantra.com/npoh