Salt Rejection Field-Test Calculator

Don’t take a rejection spec on faith — measure it. Enter your feed and permeate TDS to compute rejection and check it against the new-element baseline.
Enter a valid feed TDS and a permeate TDS lower than the feed.
Measured salt rejection
Compare against the new-element baseline at similar temperature. Replace when rejection or normalized flow can’t be restored to 90–95% of the clean baseline. Run this on a Blue Membrane sample before a full order.
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