| Hello Robert, Good for you for trying to be green. We to try to recycle, reuse and substitute greener items for landfill clogging stuff. We cook quite often in our sun oven and don't have many incandescant bulbs left in our house and have drought tolerant landscaping front and back. We've tried composting with a hole in the ground but could never keep it wet enough in our very dry climate, Then we tried a composting bin but it was very hard to turn. A tumbler seemed a good way to go but we have a horse and chickens and they are great composters eating most table scraps and garden debris and "processing" it. I haven't heard of the 25:1 rule but about whether to add water I'm sure after you have filled the tumbler and turned it a few times if you reach in and grab some compost and squeeze it you could determine if it feels too soggy, or too dry or moist which is what you would want. The rule I had heard of is to combine both greener waste and dry waste in roughly equal parts but it always seemed to me that whatever you put in if you give it the moisture and oxygen it requires the microorganisms should do the rest. Maria | 
