the reason i did the litter pans is cause the design i used was built around those. it was off of this site. but is did find one built aroud the mortor tubs and i'm going to build my next one with those. this one suits my needs cause im only gonna have 2.4 breeders. so i figured i can use two tubs for breeding 1.2, the 2 tubs for birthing, then 2 tubs for growing rats. well see if thats gonna work for now but i will eventually build the mortar tub rack when it suits my needs.
I am going to do a write up with pictures on the next mortar tub rack that I build. Its going to be a six level rack with the tubs offset to avoid snagging them on the sipper valves. I use the small mortar tubs from Home Depot.