Ebay RO/DI Units...

[Texas Reef]

Has anyone ever bought an RO/DI unit off of ebay. Some are extremely cheap (not sure about these) but some are around $130.

If you have purchased one off of ebay, was it any good?






Thanks.

 

[jdoenumber2]

I love mine(Here comes all flaming know it alls). Mine Produces 0 TDS. I am not a "Purist" however i am careful with my decisions on what equipment i purchase. Just make sure you get a TDS meter and don't rely solely on the color of the resin.

 

[Texas Reef]

Okay, thanks.


What brand do you have?

 

[Colin]

I have an "Aqua Safe" Ebay unit. It seems to be well constructed and has quick connects throughout.

The biggest problems with the Ebay units are that they are 100 GPD (which is somewhat less efficient than the 75 GPD reef units 90% crud rejection vs 98%) and they have the horizontal DI stages. If your tap water has high TDS to start with, then a 100 GPD won't cut it. The unit may put out 0 TDS water, but you'll burn through DI resin, which can get expensive.

If you're going to go with an Ebay unit, look for one with the quick connect connectors over the old compression style (much easier to deal with). Get one that holds a lot of DI resin and is refillable with bulk resin (do NOT get one that you have to buy special DI cartridges for) and figure out a way to mount the DI stage vertically. Make sure you pick up a pressure gage and a TDS meter too. Down the road, you can replace the pre-filters with better ones if you like at the 6 month filter change, and possibly change out the membrane with a more efficient one if you're spending too much on DI resin.

HTH,

--Colin

 

[BeanAnimal]

<a href=showthread.php?s=&postid=9736245#post9736245 target=_blank>Originally posted</a> by jdoenumber2
I love mine(Here comes all flaming know it alls). Mine Produces 0 TDS. I am not a "Purist" however i am careful with my decisions on what equipment i purchase. Just make sure you get a TDS meter and don't rely solely on the color of the resin.

Why insult people when you clearly are not as informed as you think you are? Just because you are "careful" with your decisions does not mean that you made informed decisions.

Nothing like insulting people that are more informed than you appear to be. Just looking for a fight; or do you think you are more informed than the "flaming know it alls"? You sure come off as a "flaming know it all" if you ask me. You just avered that everybody else is wrong and did so in a flaming manner... hrmmm

The question is what is the COST to produce a given quantity of 0 TDS water and how does that relate to OTHER RO/DI units. If you can't answer that questions then you can't talk about VALUE. If you can not talk about VALUE then what did you base your decision on?

What constitutes value?

The cost of ownership?
Customer support?
Life expectancy?
Peace of Mind?

We can talk about ANY of those aspects of a purchase. YOU have decided that 0 TDS is all that matters and the rest of us are "flaming know it alls". Hrmmm

 

[BeanAnimal]

Mounting the DI verticaly will help a bit, but it IS NOT the same as a true vertical DI stage.

The quality of the components, pre-filters, resin, membrane, etc can be suspect with many of the "eBay" units.

This is one of those cases where you do get what you pay for. Many times the "eBay" units end up costing MUCH MORE than a name brand unit from a reputable vendor.

Spectrapure.com
Thefiltertguys.biz
buckeyfieldsupply.com
purleyh20.com

Are just a few very reputable vendors. I suggest giving them a call and ask them what the difference is between their unit and the eBay units. They will talk to you about the type of water you have and what needs to be done to treat it. They are available to answer the phone and assist you before AND AFTER you purchase. Try calling your eBay vendor for help.

 

[jdoenumber2]

I only wish i was as well informed as you. Oh mighty one.

VALUE "A fair return or equivalent in goods, services, or money for something exchanged" This unit you ask of is a great VALUE. Bean have you ever owned one or did you just take everyone else's advice. I can understand the general consensus on the units he was asking about. But after all thats not what he was asking.

"Has anyone ever bought an RO/DI unit off of ebay. Some are extremely cheap (not sure about these) but some are around $130.

If you have purchased one off of ebay, was it any good?"

By the way sorry if the comment i made hit home.

 

[AZDesertRat]

Don't waste your money on e-bay drinking water systems that claim to be reef systems. Most are horrible at best. You will end up spending much more to upgrade them and make them work halfway decent that what you would spend on a good reef quality system to begin with. There are lots of reef quality systems available from RC sponsors for about $150 that will run circles around any e-bay unit. They are cheap for a reason and with RO/DI you really do get what you pay for. Cheap and a good value are two entirely different things.

 

[Texas Reef]

Thanks for the input guys. I will be visiting this site much more now. The other site I always go to (SWF) doesn't have as many experienced people.

I think I am going to with a Purely RO/DI system. $200 after adding flush kit and tds meter.



Thanks again!

 

[BeanAnimal]

<a href=showthread.php?s=&postid=9738351#post9738351 target=_blank>Originally posted</a> by jdoenumber2
I only wish i was as well informed as you. Oh mighty one.

You were the one who entered the thread slinging insults... I see that is about all you are capable of; or are you just trying to woo us with your wit?

VALUE "A fair return or equivalent in goods, services, or money for something exchanged"

Anybody can quote a dictionary, understand the definitionis another story. It is VERY clear that you do not understand the definition. You would appear to be more interested in hurling insults at people to take the focus away from your lack of understanding.

This unit you ask of is a great VALUE.

Can you explain why please? Is it of value because you like it? Where is the VALUE derived as compared to another, better equiped unit?

Bean have you ever owned one or did you just take everyone else's advice.

Why would I need to own one? A basic understanding of how RO/DI systems work is all one needs to determine how to evaluate the differences between units and their operating costs. Once the OPERATING COSTS are estimated and combined with PURCHASE COST, VALUE can start to be assigned. We do not even have to get into "extras" like quality of components, customer service, warranty, etc. If you would like, we can go through the entire system piece by piece.

I can understand the general consensus on the units he was asking about.

Something tells me you do not understand and are more interested in telling INFORMED people that they are wrong because YOU are "happy" with YOUR purchase. There is no problem with that, other than the fact that you blasted through the door and insulted those informed people with a very obviously less than informed opinion.

By the way sorry if the comment i made hit home.

Your arrogance is rather funny. Do you always start a conversation by insulting people? When you are dead wrong do you honestly think that MORE insults will better your position?

 

[dues0009]

I don't understand why you had to ruin this person's thread by taking such ridiculous offense at a passing comment made ON THE INTERNET.

 

[Texas Reef]

:uzi:

 

[Kpyto]

Texas... we'll let these two duke it out...

In the mean time, I have an e-bay unit... an Aqua Safe unit. I've had it for a while now, and have had no problems with it. A TDS reading at day 1 was zero. It's crept up to about 3 now, so I'll be changing the filters.

My suggestion... do some research - search the threads and see what you find on "e-bay RO/DI." Don't make a hasty decision, read the RELEVANT posts made to this thread, and then decide.

 

[jdoenumber2]

Blah Blah Blah....

 

[justinm0424]

I have an ebay one also. It's an dvoneb or something and it works great. I don't have a tds meter so I'm not certain on how well it works but I only have 2 snails for my cleaning crew and have very little algae problems. If I was you I'd get an ebay one then 6-12 months later replace the filters with high quality ones. All RO/DI units seem the same except for filters and meters.

 

[AZDesertRat]

The measure of success of any RO or RO/DI unit is how well the RO membrane itself works. This applies to every unit no matter where it comes from.

Traditionally the e-bay units cut corners on RO membrane quality by using either no name knock offs that are not made in the US by Dow Filmtec and do not carry ANSI/NSF certifications for drinking water use, using name brand but less efficient RO membranes or by using membranes that are not even Reverse Osmosis membranes at all but are Nano Filters which is no where near as efficient.

Another way they save themselves money and cost you more money is by using very cheap filters instead of good quality filters. This costs you money in shortened membrane life and shortened DI resin life. What appears to be a good deal ends up costing you much more in the long run.

For those who say they are happy with their E-Bay units I again challenge all of you to post your tap water and RO only TDS numbers. Any unit worth anything at all can produce 0 TDS water for at least a very short time. The proof is in how well the membrane works which directly affects how well the DI works and how long it lasts.

Quality costs money plain and simple. None of the Reef Central RO/DI vendors is getting rich off of their units. They all use name brand components with a proven track record and stand behind their products unlike the ebay vendors that are here today and gone tomorrow. Most of them would have been out of business years ago if they were relying on printed media or television to advertise. The government does not mess with e bay fly by nights but they do look at truth in advertising in other medias.

If it looks too good to be true you can bet it is. Don't waste your money on a few peoples recommendations that do not provide facts to back up their vauge claims.

I'll gladly post my results. My tap water TDS is 852, my RO only TDS is 6.2, my RO/DI is much less than an indicated 0 TDS using a HM Digital COM-100 conductivity meter, my temperature is 69.8 degrees F and the pressure is 58 psi. Those are facts. Thats a 99.272% rejection or efficiency with RO only. No e-bay unit will come close to matching that.

The reason rejection rate or efficiency is so important is for every 2% you increase your efficiency you double the life of your DI resin. That can save you a ton of money in a very short time so its worth the difference to get a good unit the first time. Don't mess with inferior ebay units.

And all housings and fittings are not the same. Pick up a good unit and then pick up a cheap one. The good one weighs about twice as much. Thats better plastic castings on the housings and brackets.

 

[BeanAnimal]

Joe,

I will take that as a simple answer. You have nothing more than insults to add to this thread.

Justin, that would depend on how you define "it works great". Honestly, if you do not have a TDS meter, then how would you even know?

Dues, people who sling insults at informed and helpfull people are the ones that ruin threads.

Now that we have that out of the way:

The first thing to look at is the RO/DI membrane itself. A DOW FILMTEC 75 GPD membrane will have a rejection rate of at least 98%. The membranes in many (most) of the 'eBay' units have 90% membranes.

So what exactly does that mean? Lets take an average input TDS of 300.

The 98% membrane will output 6 TDS into the DI resin
The 90% membrane will output 30 TDS into the DI resin

That means that the unit with the 90% membrane will use 5 times the DI RESIN that the unit with the 98% membrane will. At $20 a refill, things start to add up VERY QUICKLY.

But THAT is not the only problem. The cheaper units come with garbage prefilters. The prefilters do not do a good job of protecting the membrane. The membrane is the expensive part of the renewable components, you should protect it from damage from day one, not 6 months or a year into use!

The garbage prefilters DO NOT do a very good job at chlorine or chloramine removal.

Most of the 'eBay' units come with horizontal DI beds. This not only allows water to bypass and can cause elevated TDS in the output stream, but it also WASTES DI by not forcing the water to ever come in contact with it.

Many of the units do not have refillable DI beds, you either pay extra for their sealed garbage or have to pay more to upgrade to a refillable high quality vertical cansister (that comes with the better units).

Many of the "ebay" units come with very poor quality DI resin that has a fraction of the capacity as the higher quality resins sold by reputable vendors.

Many of the units are made with very low qaulity plastic that brittles in a short period of time. Just here at RC, you will find many posts where peoples units have failed under regular household water pressure.

Light weight steel brckets that quickly rust...

What about customer service? What about warranty replacements? The vendors listed above ALL honor their warranty and will bend over backwards to help their customers. You can find dozens of posts explaining how those vendors have sent parts free of charge and worked with the customer to ensure that everything is perfect. Try and find "eBay" threads that show that? Instead you will find horror stories.

This is really a non debate, even though some people wish it were. Some companies sell high quality reliable gear, others sell bargain basement garbage that costs more to own in the long run.

The telling sign is the fact that MOST of the eBay vendors post decieving or outright statements in their advertisements.

Some people likejdoenumber2 are too busy insulting people to ask questions and get honest helpfull answers. Instead they want you to think that the better informed people here want you to waste your money. The exact opposite is true. We DO NOT want to see you waste your money. There are predators lined up in every corner of this hobby. The least that I (and others) can do is to warn people when we see something that is too good to be true.

If you have VERY LOW (Less than 80 or so) input TDS then even the junky eBay units may be OK (if you have low chlorine and no chloramines). The rest of us with higher input TDS need to consider the overall operating cost in our purchase decisions. It is that simple.

Look at it this way. Does paying $500 for a used 1978 Delta 88 that gets 11 miles to the gallon make more sense than buying a $1500 1978 chevy "luv truk" that gets 20 miles to the gallon?

Both get you from A to B. One has horsepower the other gas mileage. If COST is your concern and you drive more than a few times a year, then the $500 vehicle is NOT a bargain at $3.00 a gallon is it? If horsepower is your concern and cost is not an object...

So that begs the question. Are you buying the eBay unit to save money or because it is BETTER? We know that it is niether better nor capable of saving money, so why buy it?

 

[jksites]

I've had an aquasafe for 2 years servicing my 90 gallon and it is fine. Customer service is great with them and replacement filters are priced in line with all others on the market. They in fact do use the DOW membranes so the cost is the same.

I've spent thousands on my tanks and spend hours and hours before I make a purchase. This is one that I am confident that I made the right choice.

Best of luck in your decision.

 

[AZDesertRat]

Give us numbers to define "fine". Lets be factual and not subjective here. Fine to you may not be fine to me or anyone else, without TDS numbers "fine" is worthless. I don't mean to belittle anyone but lets be real here and true information so buyers can base their decisions on true numbers.

 

[Reefugee]

I don't claim my unit to be the "best" unit out there. But over the past two years, it has served me well. I thought I'd share what I posted in my local club forum. I wish I had run the following test with the pre-filters that came with my AquaSafe RODI system. I bought my system 2 years ago - so it's possible that the quality of the unit might have changed.

<a href=showthread.php?s=&postid=9679466#post9679466 target=_blank>Originally posted</a> by Reefugee
There's been numerous holy wars on RC regarding RODI system. Some people swear that the cheapie Ebay RODI system works great, while others tell you that if you don't spend $200+ on an RODI, you have a piece of junk and your fish will all grow a third eye from the contaminated water.

Anyway - I have a an Ebay (AquaSafe) RODI system rated at 100GPD. According to what I have read, the 100GPD RO membrane has a rejection rate to 90%. The 75GPD unit has a rejection rate of 98%. I have been debating on converting my 100GPD RO to a 75GPD RO.

I also heard that the initial burst of RODI water is usually not that great, so it's bad to run RODI for a short period of time. It is supposed to be better to run the RODI for a less frequent but longer period of time. I decided to do some quick tests.

My RODI unit is about 2 years old. All the pre-filters and the RO membrane are originals. I have replaced only the DI five times in the past two years - usually when the RODI water reads 15+ppm. I just replaced my DI with the Funman1's DI group buy (Thanks Steve!). Below are my TDS reading from my test.

Tap water = 515 ppm (my water seems to vary between 500 to 900ppm)
RO = initially 144 ppm but after a few minutes, it read 6ppm
after DI = 0ppm
water production rate: no where close to 100GPD

So according to my calculation, my RO is removing 98.8% of the TDS. Also - it appears to confirm that running the RODI for frequent short burst is worse than running it for less frequent longer period of time.

Here is the interesting part - my RODI water has read as high as 17ppm before. I can't recall if I tested the water at the "initial burst" or after the water had been running for a while. If it was after the water had been running for a while, I am wondering if the DI could have leached some impurities back into the water.

Anyway - I just though I would share my results with the group.

Now - let the religious war start....

Minh

<a href=showthread.php?s=&postid=9686522#post9686522 target=_blank>Originally posted</a> by Reefugee
When I arrived home, my new pre-filters and inline TDS meter were sitting on my porch. I purchased the filter from AirWaterIce (great customer service). The filters were a 10 micron sediment fiter, a 5 micron Carbon filter, and a 1 micron carbon fitler. All the prefilters were replaced.

Picture of the old sediment filter vs the new one. I guess I should have changed out the filter a LONG time ago.

My tap water TDS read 546ppm. This is from the same faucet that feeds my RODI system:

This is the water after it has gone through the RODI system. The initial water quality was 50ppm, but after about 10 minutes, it was down to 2ppm. Basically the prefilter and the RO removed 99.6% of my TDS.

This is the water after it's been through both the RO and the DI. The DI was just replaced last week. TDS = 0

Now that I was done with my little test, I turned off my RODI system. About 10 minutes later, my water post-RO but pre-DI crept up to 10ppm.

So out of curiosity, I turn on my RODI system and let it run for about 10 minutes. The post-RO water read 2ppm again.

Here's a picture of my AquaSafe RODI system. I modified the DI canister so that it stands upright. The water from the RO flows through the bottom of DI canister and then exits through the top. The reason why I did this is so that the water must past through DI to exit the canister. In the horizontal position, it was possible for some water to barely have any contact with the DI resin.

Not bad for a system that I purchased for $96 (shipped) two years ago.

Minh