Found this elsewhere and just got the soilmoist today...

Shopping list:
5 gallon bucket
Holmes Fan
ONA
Soilmoist

Remove screws from holmes fan from walmart ... it does fit perfectly in the 5gallon bucket(i've tried this... doesn't even need to be bolted duct taped or secured at all)

drill holes around bucket

mix 10 cups water
1 cup ona
1 cup soil moist

Clean air now!

this wasn't my own idea but I know ona works and the soil moist added to it makes the ona last longer as it absorbs the liquid and slowly releases it.

-potlike