Have several tanks that i am setting up in my basement. A couple will be open top and i will have a total of 723 gallons of water. I have a short basement and exposed beams. How do prevent mold from building up.
Really big dehumidifier or (preferrably) an air exchanger.
Congrats on having the good sense to look into this issue. I know of lots of people who have seriously damaged their homes from tank borne humidity issues.
Depends on climate. If you are dry than not too hard de humidifiers are ok. Air exchangers are common in humid climates in newer built houses. If you do see some build up there is a product called killz it is a white spray paint but it will kill mold build up. Mold is just smelly and makes air quality less then ideal but if everyone in the house is healthy mold issues are small and blown out of proportion by the public.