Questions.

[Justin Turco]

What do you do with your wash water? How bad is it?

How often do you guys do an acid wash? I've got a neighbor who says he just adds some acid to his soap when doing a regular wash and has had good luck. Is that how you guys are doing it?

[Russell Lampron]

Justin the RO soap is a base which raises the ph while the acid lowers it. Mixing the 2 isn't a good idea because of the reaction of some chemicals when mixed together. I have only used the RO soap and water in mine mixed so that I have a ph of 11. You can do an acid wash but plan on letting it sit for 3 days. With the extended forecast that I have that isn't going to happen for a while.

[Tmeeeh]

Russell is right on. Don't mix the soap and the acid. The soap is Lye (Potassium Hydroxide) and the acid is citric acid. Both can be bought for much less from a chemical supply house. Alternating acid and soap wash works best here. Add acid until pH 2 (use paper strips or a pH tester) recirculate until 100 degrees and soak over night or up to three weeks. Always wash with soap after using acid.(the ro seems to run slower after acid and before soap) Add soap until pH 11 and recirculate to 115 degrees then rinse. It is not recommended to let the soap solution soak. Frequent washing will keep membranes going at the same rate for many years. If you send membranes to the factory for washing they wash the same as described above. They use 10 to 15 acid then soap wash cycles. Use permeate for washing. Well water doesn't work as well. Never allow any chlorine in the ro. Not even chlorinated municipal water.

All this is for washing Fluid systems or filmtec membranes made from polymide. Common names are TFC, Maple Mark 1, NF 70, NF 90 etc.

Washing Hydronautics PVD 1 membranes is said to be much easier. And use different soaps.

[Justin Turco]

Good information! You have definitely convinced me not to wash and acid treat at the same time. I have a hydranautics 4x40 membrane. How much soap should I add to my wash water? (Still to about an 11 on the ph?) First time it's been turned on this season. I am doing a rinse cycle as we speak. Wash cycle next then rinse.

[Russell Lampron]

Justin it only takes about 2 tablespoons of soap to 10 gallons of wash water.

[Justin Turco]

Done. But I never got to 110-115 degrees. Next time I'm going to preheat some permeate. Hey to the airablo or springtech guys, what to do with V1 when rinsing or washing? I Closed it and then noted some pressure on the prefilter guage. 20 psi. When V1 is open the pressure drops right down. My manuals don't mention that, they also don't tell you how to get the water out of the wash tank when your done with it. I opened valve 19 and it pumped out.... Then did a rinse like the books said. I am the type of guy who likes to have the explanation of whats happening when you flip those valves....all the Nit/Noyd details. It bothers me to run something when i don't know completely how it works. Leader was going to try to find the specific Manual but never got back to me. Just thinking out loud here. I'll be ok. Sure looks cool all set up. Now if the wx would just warm up.

Appreciate your help ya'll.

Justin