Hi everyone! After I posted the article about fake Dow membranes last time, lots of you left messages in my comment section, asking me to write a guide telling real Dow membranes apart from fake ones.

If you haven’t read my previous post, just click this link right here!

Does dow have a fake membrane?

I’ll do whatever you guys want to see. But I was on a business trip all week from Monday to Friday. I just got home, unpacked my luggage, and turned on my computer to finish this article about fake Dow membranes.

Northern China has really nice weather these days. I visited Baiyangdian Lake during my trip break. I’ll share some photos with you—isn’t it beautiful?

Now let’s get back to the main topic. I plan to split the content about fake Dow membranes into two articles. 

Today we’ll mainly talk about refurbished Dow membranes. What are refurbished membranes? 

They’re used Dow membranes cleaned and polished with chemicals, then sold as brand-new ones. If you put refurbished membranes in your water system, their salt rejection rate is usually low, only between 90% and 96%.

So how can you tell if a membrane is refurbished?

First, sellers wash refurbished membranes with chemicals to hide their old marks.Check the two ends of the membrane carefully. Look for tiny carbon or sand grains, and scratches or dents on the plastic parts.

Second, refurbished membranes have been used before, so they usually weigh more than new ones.

Third, check the serial number.Every Dow membrane has a unique serial number in the middle, just like its ID card. Each number is one-of-a-kind. You can look it up to check its production date and customs clearance time. For refurbished membranes, the production date you find will be far in the past.

Alright, that’s all for today’s talk about refurbished Dow membranes! Next time, we’ll discuss high-copy fake Dow membranes.