Uses (non-potable)*:
- toilet flushing
- HVAC cooling
- irrigation
- Pretank filtration - centrifugal
- avoid disturbing sediment and bio filter at b/o tank - take water from just below surface
- provide overflow outlet equal to inlet
- see local codes for color of piping (purple), filtration requirements for toilet water, dyes, etc.
- wait 1 yr before using water run off from new asphalt shingle roofs
Filters:
- ask about maintenance. high efficiency, low maintenance is most important
- size is based on sf of runoff area. rule of thumb: 1" on 1,000 sf = 620 gallons
- keeps debris and food for bacteria out of tank
- if additionally required, UV and carbon filters are recommended over more expensive ozonators
- indoor above grade - polyethylene recommended. steel tanks come modular to get into small spaces
- outdoor below grade - fiberglass recommended. steel is not recommended below grade.
- avoid running municipal water into tank. kills good bacteria. when dry, use day tank or separate supply.
- tank should be opaque to inhibit algae growth
- below grade tanks will have lower, more consistent temperature, which is good for the right bacteria.
*note: rainwater is naturally soft. no softeners are required.
