Thanks WH; I knew I could count on you to give me some good advice. The 4.9 PH on the RO I stated is correct. I will flush the trays and refill with 5.9 PH RO. How long should I wait till I abandon this effort? Is it possible to reuse the Rapid Rooters from the failed attempts? My regular rule of thumb on reuse is if there is no bad/unusual smell I will use them again. Thanks again for your help.:thumbsup: