another RO/DI question

[jubjub]

looking around on ebay i found

http://cgi.ebay.com/WaterGeneral-RO6...QQcmdZViewItem

and thought wow good price anyone have experience with this?

or even
http://cgi.ebay.com/7st-UV-RO-DI-TAN...ayphotohosting


keep in mind this is gonna be for my 55gal but mostly drinking...water in the area taste horrible

[SlowCobra]

You get what you pay for. There are hundreds of threads on here and very few happy Ebay RODI purchasers.

[aaron L]

Check out the filter guys RODI units.They are great with there warrantys and service

[Ruskin]

In the first link they advertise that is good for drinking water and aquarium use. Correct me if im wrong, as I havent done any research about RO/DI since i bought mine almost a year ago, but doesnt continuosly drinking DI'd water make people sick? Since its supposed to strip every thing from the water, including chlorine, wouldnt there be all kinds of things possibly contaminating it afterwards?

Something just struck me as odd, and I didnt think you would want an RO/Di unit that claims to make both drinking water and water for aquarium use. Plus, if it is DI'd wouldnt it taste... bland, and awful?

My point is, if they cant get that right I definitly wouldnt trust thier water in my tank.

Pay for a good unit, it wont cost you that much more then a Ebay one, and you wont have problems down the road. Without good quality water, fancy lights and livestock is useless.

[aaron L]

I put some RODI water in the fridge every no and then for drinking. No problems here

[anothermineral]

I drink di water every day, no problems as far as I'm concerned. I think this is an urban legend of sorts. It just seems counter intuitive to me that drinking pure water is some how bad for you. I personally have never seen any medical data to support the claims that drinking di water is bad for you.

[AZDesertRat]

E bay units are generally of much lower quality than a true reef quality system. Don't beleive the miracle crap they try to feed you on their e-bay sites. Keep in mind most do not have a true storefront and would be sued for misrepresentation or false advertising by the Federal Trade Comission and put out of business if they did. You will not find a $69 RO/DI unit that performs as well as a $150 unit period, it just does not happen or all the Sponsors and Vendors here on RC would be selling $69 units.
Expect to pay right at $150 to $230 for a good high quality RO/DI system that will perform and last as advertised. Any less and you sacrifice water quality or component life or both. You will not get things like a TDS meter, pressure gauge, RO bypass etc with cheap units so factor those necessary pieces of equipment into the cost along with an autoshutoff valve, flush valve, written guarantee they will stand behind and other things that probably are not provided.

As for drinking DI ,there is not conclusive medical proof it does anything to the human body. You would have to be on a strict DI water only diet with no solid food or any other form of nourishment for an extended period of time to possibly cause any harm. It ain't gonna happen! One potato chip and you just got most of what you have been missing. DI does taste reall bland and unappealing to most people and its kind of expensive to produce so RO is my choice for drinking and cooking and has been since 1992. Other than a nervous tic, a third eye in the middle of my forehead, loss of hearing and a persistent ringing in the ears........Honey would you answer the phone please... I'm perfectly normal.

[sawillia]

There is one guarantee on all of these Ebay RO/DI posts.

AZDesertRat is going to weigh in on it and he simply doesn't like it (ebay systems) HMMMMMM

It's simply amazing.



DO a quick search and make your own decisions.

You'll find out quickly how they work and what RO Membranes are Hype and which ones work. Once armed with your new knowledge you can simply and cheaply build an RO/DI system on your own and SAVE A METRIC BUTT TONNE of money.

At the end of the day. Clean water is Clean water.

0 TDS is 0 TDS I don't care if you get it from the Tap, a coffee filter or the washing machine.

This entire hobby is filled with opinions, subjection and decisions.

Read up on it make you're decisions and move on.

ticky ticky:

don't like the filters that come with the ebay system. Order different ones... you can even get them from other vendors..... shh don't tell anyone...

(no disrespect to Mr. Desert Rat and no attack. I'm merely stating the facts.)

[AZDesertRat]

If a prefilter about as efficient as a screen door, a granular activated carbon filter good for 300 gallons, a Chinese imitation membrane and a little hollow tube with a few ounces of outdated DI resin floats you boat the go for it. The fact remains there is a difference and its been documented over and over.

[sawillia]

see what I'm saying...

Original poster:

Please do a search and make your own decision.

Mr. DesertRat:

Notice I did mention RO membrane quality.


I'm glad to see you don't disappoint....

[Fish'InMN]

Originally posted by sawillia
see what I'm saying...

Original poster:

Please do a search and make your own decision.

Mr. DesertRat:

Notice I did mention RO membrane quality.


I'm glad to see you don't disappoint....

He responds to these threads because he has experience with the subject matter. He's not paid to answer these threads, he does this voluntarily.

Is it a coincidence that he writes the same thing every time? No, he writes nearly the same thing because it is, always has been, and always will be, true. Hell, I'm surprised he doesn't have a Cut-N-Paste response by now. But then you'd be on his case even more for spreading his lies, I suppose...


Marty

[SlowCobra]

Perhaps in your bashing of AZ you should make note of his occupation. Given what he does, I would tend to believe he would know a couple tidbits about water filtration and what is and isn't a quality product.

Your advice to buy it and replace everything is the most non-cost effective solution out there. That is what most end up doing as they quickly become dissatisfied with the Ebay units. In the end it is more expensive than just purchasing a quality unit right from the start.

[jubjub]

ahhh i was hoping to cheap out i guess...but i guess filterguys is the way to go and i will just have to break down.....btw thanks AZ...i didnt have intentions of this to become a bashing thread....just wanted opinions....

[sawillia]

I merely asked why and this Hijack isn't helping the poster....


There is/was no bashing nor was there malace. If you read that it's your fault. I plainly and matter of factly stated it wasn't a flame.



As far as just replacing for the sake of replacing that is ridiculous. IF you'd like clarity...

"Once the original media is depleted replace it with what you'd like. That's what was meant."

You'd be suprised of the pedigree of the people who lurk here.. He has a water filtration back ground... FANTASTIC he's a value in that arena... There are others of us out here that work for LAB companies that filter and DI ALL THERE water for labs... SO other people have opinions too... Imagine that. Systems that we deal with will dwarf most people's imagination... Not Mr. Desert I'm sure he's done more complicated filtration... we don't do brown water...





Again I wasn't bashing him... it just makes me wonder why that's all



My whole point was for people to make informed decisions. All too often things here are denounced based on the price one pays.

Do you really think that the little yellow tang cares how his water stays clean...I'm sure he is more concered with a clean place to live in captivity.


I can't wait for little jerseys to come out for our inhabitants that show sponsership.

Sorry for the hi jack... I merely wanted to know why...

Some people are blessed with Tap water with TDS of 85 or less.

It doesn't take $230 dollar RO systems for these parameters for those people to see a value. Once again 0 tds is 0 tds.

I built my own RO/DI Unit, I can supply TDS readings over the past year I Actually track them because I built it myself. I recycle my waste water and re filter it on an additional setup... So this Frankenstein has been running maintenance free for over a year...

And guess what... I didn't spend $150 on it...


There are options... Make your own decisions.

[carlso63]

It always amazes me that the most important bit of advice concerning buying a RO / DI unit seems to always get left out amongst all the opinionating and infighting.

And that is, to have your tap water supply tested for TDS level before you buy a unit. You can, of course, buy your own handheld TDS meter and do this yourself - or you can have someone do this for you (most decent LFS will test a sample of your water for no charge).

Then base your purification decision at least in part by your starting point.

In my case, my tap TDS runs 205 - 225 ppm depending on season, temp, etc. In my case , I bought an Ebay unit for home use. I added a dual inline TDS meter, and rerouted the DI canister from a horizontal position to vertical position. Other than that, no changes or modifications... I have made over 800 gal of *0 ppm* water so far, and have changed my prefilters once. I changed them because I read somewhere (here on RC, I thought) that it is a good idea to change them every 6 months, regardless of "what they look like" or what your TDS meter reads. In hindsight, perhaps I was too hasty. I certainly didn't change them out because of performance issues. And the supposedly "shoddy" RO membrane that came with the unit is giving me, In my case, an output of 6 - 7 ppm (RO only) on that 205 - 225 ppm input... well, that's about a 97% rejection rate... !

Anyway, my point is that knowing my TDS level beforehand allowed me to go with a lower cost, (perhaps) lesser quality unit without sacrificing the desired result (which is 0 TDS water).

Now, for anyone to come on here suggesting that in ALL cases an Ebay unit "will work" is just plain wrong. But to say that in ALL cases they "don't work" is wrong, too. It really depends heavily on what you need your system to do, and where you are starting from in terms of water quality. I remember a fellow posting several months back (from Seattle, I think) that he had tap water with <50 ppm TDS - from the tap -and he was told an eBay unit WOULD NOT give him 0 TDS water.

?????

And, for the record, let me say clearly that had my initial tests showed a TDS anywhere near the 1000 ppm that AZ Rat has to deal with, then OF COURSE I would need a "premium" unit!

Oh, and I too know a little about water quality. As a Pharm Engineer, I helped design and install a system at my Companies newest Stage II DEA / FDA Compliant Manufacturing Facility (CMF). We use a system called a Milli - Q that has a 400 gpd capacity and retails at over $18,000 (not including filters)...

Now that's what I call a "premium system"

[AZDesertRat]

The reason for changing the prefilter and carbon at 6 month intervals is to help prevent the potential growth of bacteria and viruses inside the filter housings. Once water has passed through the carbon there is no residual disinfectant left to protect you from growth. Tap water is never 100% bacteria and virus free.
It also allows you to disinfect the housings at the same time, a process that takes maybe 5 minutes and can save your life. If you have never seen slime bacteria inside an unserviced RO uniy its hard to imagine what I am talking about but suffice to say its an ugly sight and could be potentially deadly if not discovered. In my old municipal supervisor position I ran across this more than once in customers homes who basically installed the unit and forgot it was there. In one case 2 people in the household were hospitalized.
Always use high quality replacements. The reason they are there is to protect the RO membrane so cheap filters that do little in the way of treatment allow those contaminants to reach the membrane shortening its life. Talk to Randy Holmes Farley about this, he got just short of 10 years out of a single RO membrane by using good filters and doing the regular required maintenance.

I am presently working on an 8 million gallon per day RO drinking water system that is not much different than our small point of use systems but they have the advantage of cleaning the membranes in place and disinfecting them with hydrogen peroxide so its recommended and done on all sizes of units as a precautionary measure.

[sawillia]

I don't like using the clear prefilter housings like you see on some unit. I keep my unit out in the garage (mild seasons) so it see some direct sunlight. I've seen both green and red algae build up in the pre filters because of it.

AZ is right on the money with cleaning the prefilters and there cannisters as a regular PM step.

My TDS at the tap ranges between 55 and 85... I consider mysefl extremely lucky to have city water with those parameters

[HDAlien]

For what it's worth, I bought the very unit mentioned and the filters only last about 3 months before the TDS's started creeping up. Now keep in mind, my incoming TDS is only 120, not bad by most standards. I upgraded to the Spectrapure unit on AZ's recommend and could not be more pleased. Oh yes, 2 months in and still 0 TDS. You do, in fact, get what you pay for.

[kysard1]

I upgraded from a cheap ebay unit with a GE 75 GPD membrane to an expensive filter guys with the spin doctored 75 GPD Filmtec., just to see if there would be a real improvement with my water
both gave 94% rejection.

You have to understand that no membrane gives 98% rejection of every contaminate. All water supplies have different contaminates. If you have easy to filter dissolved solids you may benefit by spending the extra $200. Odds are you won't.

Being a WWT operator in of itself does not make one an expert in RO. AZ has learned a lot more about RO than most WWT workers I have dealt with. But it is a complex issue, if you know what to look for you can get an ebay RO for 1/3 the price and not lose any real world efficiency. However some Ebay units are garbage. It is safer to get a spectra-pure if you don't know what to look for.

The first thing you should do before buying any unit is determine how much CO2 and TDS is in your water supply. This determines how much RO efficiency you need. For example if you have 500 ppm TDS and 1 ppm CO2. You should buy a spectra-pure. If you have 50TDS and 200 ppm CO2 buying a spectrapure is a waste of money. This is because the CO2 will be the rate determining factor of DI resin depletion.

[AZDesertRat]

kysard, thats absurd. A more efficient membrane is still going to extend the life of the DI regardless of CO2 or not. My water is high in CO2 and always has been. I changed from a Watts Premier to a Spectrapure and my resin life went from 150 gallons per cartridge to 630 gallons per cartridge with no ther modifications.
As for being an operator or worker, I was a supervisor for 17 years and a manager for 5. I left the municipal sector after 33 years and now work for one of the largest environmental engineering firms in the world and teach engineers how to do things the right way every day. Its my job. Just because it says so in a textbook does not mean a hill of beans to me. I am used to ticked off engineers and it doesn't bother me in the least, they know I am right more often than not.

[kysard1]

AZ you are missing the point.

Here is an example where high CO2 makes buying a spectrapure a waste of money.

CASE 1 WITH 90% REJECTION AND HIGH CO2

70 TDS water supply. CO2 150 ppm

RO Membrane Rejection 90% gives 7 ppm + 150 ppm CO2.
DI chamber lasts 5000/157 = 32 GALLONS



CASE 2 WITH 98% REJECTION AND HIGH CO2

70 TDS water supply CO2 150 ppm

RO Membrane Rejection 98% gives 1.4 ppm + 150 ppm CO2
DI chamber lasts 5000/156 = 33 GALLONS


Wow you get a whole gallon more resin life with the 98% membrane.

Why would someone with water like this spend big bucks on a Spectrapure ?

[vegaskid11]

I bought the identical ebay unit and have used it for approx 30 days. I filled my 600 gallon system with it and have been topping off with it since. I just got my TDS meter yesterday and tested it for the first time.

Water coming out of the unit measures 140 ppm

Maybe i found the source of my issue (dino problem)

In vegas our tap is crappy. It comes out at 540ppm.

This is a supposed 6 stage unit. I really like it because it has the tank for drinking which is split with a seperate supposed taste filter. It also has the auto shut off which is nice.


Do you guys think I should scrap this and order a spectra unit or should I change the guts out on this unit?


AZDesert has always given me great advice. He is one of the few on this website whose advise I do not question. Thanks.

[carlso63]

Originally posted by vegaskid11
I bought the identical ebay unit and have used it for approx 30 days. I filled my 600 gallon system with it and have been topping off with it since. I just got my TDS meter yesterday and tested it for the first time.

Water coming out of the unit measures 140 ppm

Maybe i found the source of my issue (dino problem)

In vegas our tap is crappy. It comes out at 540ppm.

This is a supposed 6 stage unit. I really like it because it has the tank for drinking which is split with a seperate supposed taste filter. It also has the auto shut off which is nice.
Do you guys think I should scrap this and order a spectra unit or should I change the guts out on this unit?
AZDesert has always given me great advice. He is one of the few on this website whose advise I do not question. Thanks.

{ sets up soapbox and climbs up, shaking head...}

This is EXACTLY what I JUST posted about...

See my post above. It CLEARLY states that the eBay units are only good f your tap water is fairly low TDS... (In an earlier thread I wrote that I thought the highest TDS it could handle efficiently would be around 250ppm...) If you KNEW going in you have "crappy water", with a TDS of 540ppm - WHY would you buy the eBay unit anyway???!!!

And I also said the FIRST & SMARTEST THING ANYONE SHOULD DO is to test your tap supply FIRST... which, AGAIN, you seemed to know should have been done - but, AGAIN, you didn't do it...?

And if AZ "has always given you great advice...I do not question it" then why didn't you FOLLOW it? I can flat-out guarantee you if you asked for his advice that HE didn't tell you to go out and buy that eBay unit

Sorry if I sound harsh... but, to me, you sound like you were at least a little informed beforehand re: your water quality - and THEN made a poor choice anyway... again, IMO, that's worse than the total noobie; who, at least, is totally ignorant and has no idea what to do or what to look for when he makes a poor choice...

And cases like yours become "ammunition" in threads where I get told my eBay unit is "a POS that flat out doesn't work", etc.

{steps down from soapbox...}

Anyway...At this point - since you already have the unit - I would say try getting better filters and a membrane and see where you end up. Worse case, you can always buy that Spectra and then keep the other filters as "spares"...

[vegaskid11]

First off loud mouth. I have never asked AZ for RODI advise. Second, I bought the unit before I realized the quality of membranes and filters was so widespread. Obviously if I would have read this thread then I would not have gone that route. I didnt go cheap either. This unit was 150 dollars with all the damn drinking water tanks and connections I needed.

Your lousy attempt (soapbox analogy to emulate that you are lecturing me) to discuss reef topics would be better served elsewhere. You dont know me so dont ever try and lecture me.

THESE BOARDS ARE MEANT FOR DISCUSSION. OBVIOUSLY YOU GET OFF TRYING TO TELL OTHER PEOPLE ABOUT THERE MISTAKES

YOU ARE A PERFECT EXPAMPLE OF SOMEONE WHO DOES NOT BELONG HERE. GO GIVE YOUR SLANDER AND RIDICULE TO SOMEONE ELSE.

I posted my experience after reading this thread to back up the fact that ebay units are not high quality.

I did not expect for someone who is caught up in thinking they are a water expert to try and slam me. Get a life loser.

[kysard1]

Even the worste membranes aren't that bad if setup right. What is your incoming pressure?