The RO Bucket has used two different membranes over the last two years. We were using the membrane solutions ones but have since sourced a higher quality, tighter wound 400gpd membrane (if you look at the ends of the two there is a clear difference). The newer ones we have sourced have a pH rating from 2-12 (most TFW membranes will). In addition to their pH parameters, they recommend flushing with 1% NaOH solution/.25% sodium dodecyl sulfate (which is what we make up in our preservative vials). You would then neutralize that solution if necessary to get the desired pH range (I have made a lot of solutions with a lot of different water sources and have never gotten over a pH of 12).

Msbouchard - do you have the "Jozzon" membranes or the older ones?