EBay RO/DI unit review

jtgordon20 · Dec 22, 2012

I figured this would be the spot to post this.
I'm not trying to sell this product. I am merely letting others know about it to spread the word of an inexpensive way to gain access to clean water that is a necessity of reef keeping.

My girlfriend got me this filter as a side Christmas gift. I'm not sure if I can post a link but one can simply search, "portable RO/DI," on eBay and find it.

It was ordered on Sunday, shipped Monday and arrived Tuesday (came from California and I'm in Las Vegas) no damage to box or product. Comes with necessary tubes and attachment to connect to the sink (additional attachments must be purchased from seller)

I ran it for about an hour as directed and here are the results

0 TDS

Sharr your experience also
Questions are welcome

jedimasterben · Dec 22, 2012

What's your starting TDS and what is the TDS after the RO membrane?

jtgordon20 · Dec 22, 2012

Before filter TDS is 460ish. After membrane, I'll have to check. Let me put it back together lol forgot to measure.

jtgordon20 · Dec 22, 2012

Coming out of the membrane is 10. Will I be expecting the DI resin to exhaust faster than average?

jedimasterben · Dec 22, 2012

jtgordon20 said:
Coming out of the membrane is 10. Will I be expecting the DI resin to exhaust faster than average?

From 460ppm, I think it would exhaust fairly quickly, especially depending on the DI resin. I'd say that as soon as you start to see TDS go up from either the membrane or after the DI resin (you should test both each use) to replace the membrane with a Spectrapure Select and the DI resin with Spectrapure's SuperDI.

AZDesertRat · Dec 22, 2012

About average, your rejection rate is 97.8% which is respectable but could be better with a unit such as Spectrapure which only cost $125 and use full size, low mircon absolute rated sediment filters and carbon blocks, a specially treated and batch tested high rejection rate RO membrane and a full size 20 oz vertical refillable DI filter. My tap TDS is 630 and RO only TDS is between 2 and 3 so DI lasts about a year in my case.

A couple disadvantages with the portables is they use smaller, higher micron rated filters that cost more to replace, are harder to find, do not protect the expensive RO membrane as well and need replacing more often so the costs ends up being more than a full size system after about the first year of use. You will also need to fasten it all to a piece of plywood or something or it will constantly be leaking from the fittings being moved around.I really try to discourage people from buying the portables but you have a great girfriend for thinking of you.

My Sister and her husband and my Mother all live in Henderson!

fyrfytr · Dec 23, 2012

Looks like PVC and macro line tubes....wonder what the DIY cost of that would be

jtgordon20 · Dec 23, 2012

This was merely a way to make things easier with beginning a build for a larger tank. I will defentily try picking up a better quality RO/DI. Until then I will be monitering the TDS and if I need to, I can order replacement filters on everything from eBay.