PH level for wash Solution

[Quabbin Hill Farms]

Does anyone know what the .PH. level should be for washing a set of Filmtech XLE 4021 membranes?

thanks

[WESTVIRGINIAMAPLER]

I have a Filmtech XLE 440 and Dow Website shows maximum PH of 12 at 95 degrees. I am washing mine around 11 PH with a temperature of around 100 degrees. I have a 8" membrane and 1 tablespoon of pure food grade Sodium Hydroxide takes it to 11 to 11.3 PH.

[coyote]

Where do you purchase the food grade sodium hydroxide?

[WESTVIRGINIAMAPLER]

$ 13 for 2 to 3 lbs on ebay and will last for several years. I soap wash my RO every time I use it and put a new filter in every time.

[Dennis H.]

Hey Brandon, do you treat your waste RO wash and soap liquid in any way before sending it to drain?

I tried to do a cleaning with sodium hydroxide and once done neutralizing it but it did not work, so I just diluted it really good and sent to to outside.
Someone on here told me that baking soda could be used for both the acid and soap wash. I thought baking soda would only work to counter and acid.

[Dennis H.]

Oh yeah I got my sodium hydroxide and muratic acid from Duda Diesel down south, very good prices and if I remember correct if you get a certain amount of stuff it is frees shipping.

[Quabbin Hill Farms]

Brandon how much water are you using with the one tablespoon of sodium hydroxide?

[WESTVIRGINIAMAPLER]

My wash tank holds about 15 gallons, so I have it about half full of hot water plus all the water in the 8" fiberglass vessel and inside the membrane which is quite a bit more, not sure exactly how much.

[Quabbin Hill Farms]

OK thanks Brandon so you are using potable water to wash not permeate?

[doocat]

Does anyone know what the ph should be for an acid wash?

Thanks, Craig

[WESTVIRGINIAMAPLER]

Using hot distilled water off steamaway to wash with.