A good question. I think you might need some if it is last that long, but I'd wait for the official response! 😉
Other way round Bob 😉 . Keeping the solution acidic prevents the reaction between PO4 and Fe in the Trace, P-Sorbate prevents the mould 😉Bobtastic said:I believe that the acid is to prevent mold/fugus growth and and the P-Sorbate is to prevent unwanted reactions with the trace.