Had a rear tire go flat on my 300 hr B7800. Repair guy removed tire and showed me the pitted and corroded rim. He blamed it in the calcium/water mix and Kubota's poorly made rims. He then installed a tube and refilled it with the mix, saying the rim would eventually puncture the tube. Owners manual said it would not hurt tire, tube or rim. That's just not right. THIS site said that even if the tire is tubless, a tube should be installed before adding calcium/water mix to prevent corroding the rim that will then ruin the seal. I think the Kubota dealer that put this stuff in the new tractor tire should have know what would eventually happen. What a shame!!