I should have done an update but i got rid of that tub because they were chewing thru it like if it was candy so i went and build a 3 shelf mortar tub rack althouth i could have easily made it four shelves but no biggie, i can always adjust it if needed, here's a pic. so from my little expirience i would recommend the rack.
wow, that looks like a VERY easy DIY rack! i think i may build something similar once we get into a new place.