I switched to "Stall bedding" from Tractor supply for the rats and tehy have been sneezing a lot more so I am going to go to something else. I was thinking of going back to aspen but wanted to know what other cost efficient options there are. Aslo, would lining the tubs with kity litter be ok to do. Not having any problems with smell thanks to the 2 newest products I am now using.