I get aspen from concord pets ( it an 8.0 cubic ft bag compressed for about 25 bucks I have 29 snakes aright now and can do evey tub about 2x or more ) I been dumping the old stuff outside and using it for flower bed mulch. I think it the kaytee brand ( need to pick up about 2 bags of it and another 5 of pine for rodents)
Ask your pet shop cause they may be able ot specail order it for you ( I had to and then they just keep about 2-3 bags in since I refered a few other to them )
I will just be so glad when the hatchlnigs are all eating this month out of the egg and not eating getting old.