What PH on a PVD1

[mrnorthshore]

Does anyone use the pvd1 membrane in there RO and what PH do you bring your wash to? I have a new D&G 600 and I called the dealer (D&G) today and asked them because it did not say in the manual what PH to bring it to. They looked for about 10 -12 min in there books and could not find anything then they came back after asking a teck and said the it should be around the PH of 10.Does this sound right? Just want to see what people who have been useing the PVD1 for years are bring there PH up to on the wash? Thanks Paul

[Tmeeeh]

This is the third year on the PVD 1 membranes for us. A Ph of 10 is usually plenty. You can get them clean with much lower PH than 10 if they are not too dirty. It really depends on the sap and how much pressure you are using and for how long while concentrating. Lower pressure concentrating makes easier washing. Most of our concentrating is done well under 300 PSI only the final concentrating goes higher for a short time but we always stay under 400 PSI. Usually the first half of the season we only use soap every third day.. mid season every other day and at the end of the season every day. Also we use citric acid followed by soap once or twice during the later part of the season. I have heard that soap washing eventually breaks the PVD 1 membranes down and they begin to pass sugar. I've tested for sugar by boiling down a gallon of concentrate until there is only a tablespoon or so left and then using a refractometer. I have been finding that there is a very small amount of something in the permeate. Whatever it is, it tastes bitter, not sweet.

[Mark]

Check this page out.
http://www.hydranautics.net/docs/tsb/tsb102.pdf

[mrnorthshore]

Thanks Mark and tmeeh, The hydranautics website looks like max would be 9 PH. Thanks for the info Mark. Mark we got about 50 gallons yesterday and they are talking about a high of 37 today so our season might just start soon here. Thanks again Paul