To follow my previous reply, it appears the "RAL" you refer to is "recordable allowable limits" and 4800-5100 is the recordable allowable limits for "Microbial ATP" which is measured (see my previous post) in RLUs (relative light units) for ATP measurement. Thus...
ATP is a bio-chemical (adenosine triphosphate) found in all living cells. Testing for ATP in water samples has become a popular means to supply information as to the relative microbial count, activity or cleanliness of the water sample. The amount of ATP is proportional to the number of living...
I am in the field of industrial water treatment and deal with the potential reuse of reject (blowdown / bleedoff) water ... I would need more info as to the actual water chemistry of your 4-5 cycle bleed/blowdown water ... specifically: pH, Ca & Mg hardness, alkalinities, silica, sulfates...
