I currently I think head count was 54 Breeders. My tubs consist of 1.3 up to 1.6. I get Insnane sized litters as some here will know the Record set.
I clean every 3 days as having 1.3 and 1.6 in tubs along with 50+ fuzzies gets nasty quick. The poop isnt hte problem, its the constant pissing and the babies peeing adds to it.
Also dont forget about a grow out tub. Once my rats are 4 weeks old they go in a tub together till their 50-75g then gassed. With my 54 breeders im gassing close to 100 smalls a month while feeding off 20 live a month.