“I am looking for some input on building a reclaim system to reclaim my automatic carwash water.”
Here are some of the basics.
If you want to design, begin with recovery system. In-bay automatic is slope of wash-bay floor and the collection pit.
Waste from pit is normally routed to oil/water separator then sanitary sewer. If you want to use waste-water to wash cars, it must be collected at or after separator but before sewer. How you do this depends on design/size.
Regardless, waste-water must be drawn-up from underground with sump pump. Once it has been pumped up to surface, it must be processed into product water.
Generally, first stage of is a re-pressurization pump to force water through the system, basket filter to trap debris and cyclonic separator that creates centrifugal force that whirls water and forces particles out of the flow – about 80 percent of particles 70 microns and larger.
Filtration is used to further reduce particle size in water. This can include granular media, bag and paper filters, polypropylene filters and ultra and self-cleaning filtration to remove solids in waste-water down to 5 microns or “product water” that is sufficiently “clean” to wash vehicles.
Many reclaim system inject a stream of artificially generated ozone (usually corona discharge).
Ozone is a highly reactive form of oxygen that “de-germs” waste and prevents pit odor. Ozone aids in flocculation - improves clarity and reduces total suspended solids by causing particles to bind together and then precipitate down in water.
It is suggested reclaim water for in-bay carwash is best used for high-pressure like wheels, side blasters and touch-less wash pass or lubricating brushes in a friction wash.
For specifics, I would seek out experts like Dean Taylor and others.