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jcurella
01/17/2015, 11:34 AM
Hi, I'm getting ready to order a r/o counter top unit, and had a few questions.
I've noticed a variety of these units on ebay for about 70-80 bucks which is in the price range. Some of them are 4 stage, and some are 5 stage. I've also noticed that some have di and some don't. They also advertise different filter combinations. I was just wondering which would be the best one in the price range I mentioned for a reef tank. these are the once I am looking at: http://www.ebay.com/sch/i.html?_from=R40%7CR40&_sacat=0&_nkw=counter+top+reverse+osmosis+system+aquarium&_sop=15
Thanks, Joe

dkeller_nc
01/17/2015, 12:07 PM
That's quite inexpensive for a 4-stage set-up; suspiciously so. My guess is that the savings has been achieved by using a lower-quality carbon, TFC RO membrane and DI resin cartridge. That still might be adequate, but one concern I'd have is that since the carbon and DI cartridges aren't the standard shape/size, whether you'd have to buy "special" ones that are more expensive.

In other words, you might be buying a "pig in a poke".

downbeach
01/17/2015, 12:40 PM
I would get a real one:

http://spectrapure.com/RO-RODI/RODI-SYSTEMS/Refurbished-90-GPD-RODI-System

jcurella
01/17/2015, 02:11 PM
I'd prefer to get one of the counter top units since I live in a small studio, and it's a rental. Space and installation is an issue.
With that being said, I really don't know anything about ro, so I have a lot of questions. would an ro system with di be recommended for a reef tank? I saw one that advertises dual di. Also saw one that advertises re-mineralization. Would this be recommended as well?
I know these units are cheap, but I'm sure they are better than using tap water.

BrentH
01/17/2015, 07:50 PM
Pig in a poke ... I agree wasting your time with the cheaper units ... I wouldn't trust useing one on my tank but I guess it depends on how serious of a reefer u want to be?

dinonightmare
01/17/2015, 11:04 PM
I agree with the others. Is it worth spending $80 to only have the unit go bad in 2 months and then have to spend another $180 to get a good unit? I would check out Bulk Reef Supply RODI units. They are good quality for a good price. Also, I would definitely get a RODI unit and not just a RO unit as in reef tanks it is most important to have 0 TDS. Also, make sure you get a TDS meter to monitor your water purity to see when you have to replace the filters or DI resin down the road.

jcurella
01/17/2015, 11:19 PM
Ok, Let me make this clear. I CAN NOT AFFORD THE MORE EXPENSIVE UNITS THAT EVERYONE RECOMMENDS. Is it really that hard to believe that these tabletop units are not legit after 20 years of r/o innovation? I've got a lot of criticism from the "pros" But none of them seem to know anything about these cheaper units.
My questions pertained to stage/di/filter configuration.
But everyone seems to want to be "pros" and recommend the $$$ aspect of this discussion.
I've been running reef tanks with fish and soft coral on treated tap water with no problems for the last 5 years.
Excuse me for not being a pro...
Why is everyone more interested in criticizing the units I am looking at, instead of answering my questions about ro/di? . I'm simply looking for something better than tap water. I'm not privileged enough to afford the systems people are recommending. Even if the systems I am looking at are cheap. They are still way better than tap water.
Yes I am taking my hobby serious. Why do I have to be rich to be a "pro."
All I've heard about the units I am looking at is speculation, and guessing.
Which tells me people commenting her don't know [profanity] about these units.
I wouldn't be surprised if these "newer/modern units are actually way better than the overpriced stuff people are recommending.
If you can't answer the questions I posted, then you are not qualified to do so.
Brushing them of with no explanation tells me you don't know [profanity]. Thanks for the help...

2_zoa
01/17/2015, 11:43 PM
I'd prefer to get one of the counter top units since I live in a small studio, and it's a rental. Space and installation is an issue.
With that being said, I really don't know anything about ro, so I have a lot of questions. would an ro system with di be recommended for a reef tank? I saw one that advertises dual di. Also saw one that advertises re-mineralization. Would this be recommended as well?
I know these units are cheap, but I'm sure they are better than using tap water.

Yes, RO/DI water is recommended for a reef tank. Dual DI should not be needed if the unit is built correctly. I personally wouldn't have any filter that added minerals back into the water. Who's to say what minerals should be added back and in what concentration of each? Yes, I know bottled water says minerals added.

I'm a little skeptical about the unit. It's sold as a 75 GPD but, if you look up the RO membrane separate. It's sold as a 50 GPD membrane. I'm also not sure why the membrane is so cheap to purchase on it's own. 15 bucks seems a little on the low side. Either the rest of the RO/DI companies are ripping us all off or it's a cheap membrane. I just don't know. Do you know your current water TDS reading? Your gonna want to know that as well as what the filter unit is actually putting out. So, your gonna want to get a TDS meter. You simply can't trust that it's putting out 0 TDS and for the specified time frame for the filters. It has to be measured.

To me, it all comes down to cost. I understand the space thing, I once lived in an apartment. A so called, "real RO/DI" is only taller and not any longer then the one your looking into buying. They can also be hooked up in the same manner as the one your looking to buy. So, price is where it's at. If this is what you can afford, then yes. I'm sure it's better then using tap water. It would be nice to know what your water reads to be able to determine how much better. Some folks have some really good water. Mine is 70-85 ppm out of the tap. So the filters on my RO/DI (Water General brand) last a long time. You might like this unit. A touch more in price yet, better quality IMO.
https://filterdirect.com/product_info.php?cPath=21&products_id=256

2_zoa
01/17/2015, 11:58 PM
Ok, Let me make this clear. I CAN NOT AFFORD THE MORE EXPENSIVE UNITS THAT EVERYONE RECOMMENDS. Is it really that hard to believe that these tabletop units are not legit after 20 years of r/o innovation? I've got a lot of criticism from the "pros" But none of them seem to know anything about these cheaper units.
My questions pertained to stage/di/filter configuration.
But everyone seems to want to be "pros" and recommend the $$$ aspect of this discussion.
I've been running reef tanks with fish and soft coral on treated tap water with no problems for the last 5 years.
Excuse me for not being a pro...
Why is everyone more interested in criticizing the units I am looking at, instead of answering my questions about ro/di? . I'm simply looking for something better than tap water. I'm not privileged enough to afford the systems people are recommending. Even if the systems I am looking at are cheap. They are still way better than tap water.
Yes I am taking my hobby serious. Why do I have to be rich to be a "pro."
All I've heard about the units I am looking at is speculation, and guessing.
Which tells me people commenting her don't know **** about these units.
I wouldn't be surprised if these "newer/modern units are actually way better than the overpriced stuff people are recommending.
If you can't answer the questions I posted, then you are not qualified to do so.
Brushing them of with no explanation tells me you don't know ****. Thanks for the help...

You posted while I was typing and researching some info for you.

Give the expert a shout. They make the heart and soul of the unit your looking into buying.
http://www.aquamembranes.com/contactus.php

jcurella
01/18/2015, 05:55 AM
Thanks 2 zoa! Most helpful reply so far. Appreciated...

dkeller_nc
01/18/2015, 09:37 AM
I can assure you that not all of us are wealthy, and most of us that have been in this hobby for a while realize that it can be quite expensive.

What we also realize is that attempting to force a budget on a particular piece of equipment, be it lighting, heaters, pumps, skimmers or RODI units can sometimes result in more expense than paying an incrementally higher price in the first place, because the particular low-budget piece of equipment turns out not to be adequate or even functional, and winds up needing replacement.

And that's what we're trying to tell you in this case. It might be the case that the units you're considering are far preferable to using tap water. But if you wind up having to replace the unit because of poor performance and/or expensive consumables, it might not be better than using dechlorinated tap water and waiting a little longer until you can afford a better piece of equipment.

GainesvilleReef
01/18/2015, 11:48 AM
I can assure you that not all of us are wealthy, and most of us that have been in this hobby for a while realize that it can be quite expensive.

What we also realize is that attempting to force a budget on a particular piece of equipment, be it lighting, heaters, pumps, skimmers or RODI units can sometimes result in more expense than paying an incrementally higher price in the first place, because the particular low-budget piece of equipment turns out not to be adequate or even functional, and winds up needing replacement.

And that's what we're trying to tell you in this case. It might be the case that the units you're considering are far preferable to using tap water. But if you wind up having to replace the unit because of poor performance and/or expensive consumables, it might not be better than using dechlorinated tap water and waiting a little longer until you can afford a better piece of equipment.

Could not agree more.

bertoni
01/18/2015, 01:53 PM
The RO membrane in the unit posted should be okay. The other parts of the filter might need replacement fairly quickly, due to their small size, but should work if you can find quality components. I'd check the cost of new carbon and DI cartridges especially, since proprietary sizes can be expensive.

Reduck
01/18/2015, 03:21 PM
I actually had one of those units from when I only had a 12g tank. It makes 0 TDS water. It is very, very slow. (On a well, no booster pump) If you only need a few gallons a week and don't want to carry bottled water home, it's fine. Just get a TDS meter, keep it calibrated, and check its output from time to time. I can't vouch for its lifespan as I only used it for under a year. Still, it put out about 100+ gallons in that time.
I've since upsized my tank and have a full size unit.

jcurella
01/18/2015, 04:50 PM
Sorry if i came off a little harsh. I was just a little irritated at first that more people were shoiting do down my plan, rather than answering my questions. I have excellent filtration and don't do water changes as often as most people, so the unit would not get as much use as other hobbiest might use it. I get my water tested regularly at my lfs, and they always tell me it looks great. They dont even know that i use treated tap water. But I've been wanting to go r/o for a long time now. I've already invested a small fortune in lighting, filtration, and stock. I really can't affored any of the more expensive units right now. But honestly I'd be happy if i could get at least a year out of these cheaper units. Thanks Bertoni and Reduck for your insight.

outssider
01/18/2015, 05:09 PM
It should work fine. the biggest problem with these units is the di canister is horizontal. after a short time the resin will tend to settle and the water will flow at the top of the canister where there is little or no resin (because it's settled). you need to re-pack these canisters every once and a while.

2_zoa
01/18/2015, 10:23 PM
Sorry if i came off a little harsh. I was just a little irritated at first that more people were shoiting do down my plan, rather than answering my questions. I have excellent filtration and don't do water changes as often as most people, so the unit would not get as much use as other hobbiest might use it. I get my water tested regularly at my lfs, and they always tell me it looks great. They dont even know that i use treated tap water. But I've been wanting to go r/o for a long time now. I've already invested a small fortune in lighting, filtration, and stock. I really can't affored any of the more expensive units right now. But honestly I'd be happy if i could get at least a year out of these cheaper units. Thanks Bertoni and Reduck for your insight.

A little more info in the first post would have been nice. IMO, others weren't shooting down your plan. They were looking out for your best interests over the long haul. Their responses could have been a little more in depth as to why they have that view on the subject. Never the less. I really don't think folks on here are malicious and out to get anybody. I believe that if your after a short time frame to use on of these units, you'd be just fine. In fact, I don't see why you couldn't just add to one of these units to make it a "real RO/DI" unit. It could be switched over to the more common sump/filter setups very easily.

I do think it's awesome that your trying to do all that you can for your aquarium as fast as you can. :thumbsup: Stay dry and please keep us informed if you do purchase one of these units. It could be a great insight or help a lot of folks get their feet wet in the world of RO/DI. Others may see this as a great building block and not have an issue making the unit better.

It should work fine. the biggest problem with these units is the di canister is horizontal. after a short time the resin will tend to settle and the water will flow at the top of the canister where there is little or no resin (because it's settled). you need to re-pack these canisters every once and a while.


My DI beds are horizontal. I haven't changed any of my filters since I bought the unit. It's been a long time.........maybe, 3-4 years. The unit still makes zero TDS. While I don't advocate this as a common practice. I choose to really push the limits of the filter based on my usage. I wish I could say as to how many gallons the unit has made. I just ordered calibration solution for my TDS meters so I can verify that they are not telling me a lie.

jason2459
01/19/2015, 12:47 AM
...

My DI beds are horizontal. I haven't changed any of my filters since I bought the unit. It's been a long time.........maybe, 3-4 years. The unit still makes zero TDS. While I don't advocate this as a common practice. I choose to really push the limits of the filter based on my usage. I wish I could say as to how many gallons the unit has made. I just ordered calibration solution for my TDS meters so I can verify that they are not telling me a lie.

I find this hard to believe that you are still getting 0 TDS out of a RODI unit after 3-4 years regardless of the DI cartridge orientation. Around how much water are you producing a month? Are you routinely flushing the RO membrane? What is the source TDS and after RO tds? How many DI stages do you have? What is the TDS level going into the last stage if multiple DI stages?


For many with regular usage with things like daily/weekly top off and monthly or more often water changes after 3 years the RO membrane is likely needing replaced. After a few weeks to months DI is usually needing to be replaced based on several factors of course. (vertical placement is optimal). Carbon and sediment filters around every 6 months or so. Again all depending on several factors.

Masoch
01/19/2015, 07:46 AM
The EBay seller's replacement filters, http://www.ebay.com/itm/REPLACEMENT-PORTABLE-COUNTER-TOP-DI-RO-AQUARIUM-REVERSE-OSMOSIS-WATER-FITLERS-/151333207299?pt=LH_DefaultDomain_0&hash=item233c297d03 , are the same price as BRS', http://www.bulkreefsupply.com/brs-4-stage-value-replacement-filter-kit.html .

The BRS filters are, IME, of higher quality (possibly not a major concern for you) and larger (able to filter more water before needing replacement). I'm not sure what the difference will be, but I'd hazard a guess at 2 or 3x longer life for the BRS filters. In the short term, the small EBay unit will undoubtedly be cheaper than the BRS one. But, after replacing the filters 3 or 4 times, the BRS until will come out ahead. This widget,
http://www.bulkreefsupply.com/mur-lok-garden-hose-utility-sink-adapter.html , will let you hook up most RO units to a sink.

One other thing is that the BRS unit uses standard filters -- you can source them from a variety of retailers. You can also add gadgets to it as your budget allows (drinking water reservoir, pressure gauges, and so on).

I believe the more measured response to your question is that the EBay unit: 1.) is better than tap water; 2.) is inexpensive to purchase versus an RO system using standard 10" filters; 3.) is more expensive over the longer term than a standard unit; 4.) uses lower quality filters.

IME, my choice would be a basic RO (no DI) system from a reputable dealer with a sink adapter. You'll be far better off than you are using tap. Add DI when your budget allows.

jason2459
01/19/2015, 08:17 AM
I find this hard to believe that you are still getting 0 TDS out of a RODI unit after 3-4 years regardless of the DI cartridge orientation. Around how much water are you producing a month? Are you routinely flushing the RO membrane? What is the source TDS and after RO tds? How many DI stages do you have? What is the TDS level going into the last stage if multiple DI stages?


For many with regular usage with things like daily/weekly top off and monthly or more often water changes after 3 years the RO membrane is likely needing replaced. After a few weeks to months DI is usually needing to be replaced based on several factors of course. (vertical placement is optimal). Carbon and sediment filters around every 6 months or so. Again all depending on several factors.
To clarify, hard to believe its producing 0 TDS after 3-4 years with out changing any of the media during that time frame.

jcurella
01/19/2015, 01:58 PM
Thanks again for all the answers, and suggestions. I orderd the unit for 85 bucks. Even if it works for the short term, I'll be happy.

2_zoa
01/19/2015, 06:13 PM
I find this hard to believe that you are still getting 0 TDS out of a RODI unit after 3-4 years regardless of the DI cartridge orientation.
Around how much water are you producing a month? Currently I'm producing about 32 gallons a month. That's top off and water changes.
Are you routinely flushing the RO membrane? No, I haven't picked up the back flush kit yet
What is the source TDS and after RO tds? Making water last night the TDS meter said 82-PPM on the incoming water
How many DI stages do you have? I have two small DI cartridges.
What is the TDS level going into the last stage if multiple DI stages? I don't know. I've never measured the TDS anywhere else other then the feed water and after the DI.


For many with regular usage with things like daily/weekly top off and monthly or more often water changes after 3 years the RO membrane is likely needing replaced.
After a few weeks to months DI is usually needing to be replaced based on several factors of course. (vertical placement is optimal). If this was the case, I'd look into why my DI resin wasn't lasting for a longer period of time. A few weeks is a little wacky. Or even a few months. I'd look into getting a much better rejection rate or upping the pressure on my RO membrane. Or something.
Carbon and sediment filters around every 6 months or so. Again all depending on several factors.Yes, I should have replaced those many times over. I just haven't. They all still look new. I know the carbon must be used up by now but....

So, your post got me thinking. So, I went back and found an old thread on another board about my old 29 Bio Cube. That's when I bought the unit. It came home with me on the 19th of OCT 2009.:eek2:

The RO/DI unit has been through two tanks (a 29 bio cube & a 20L) and is now servicing it's third, my 65. Neither of my tanks have ever had any real sumps. I've also played with a 2.5 gallon tank. It's been up and down.

As to how much water I use, well. I'm not a big proponent on water changes. I just never have been. I did them in the beginning with the bio cube cause that's what was recommended when I bought the tank. I did those water changes with tap water. That tank was run on tap water for a good while. I've only really just started to change water on a weekly basis in my current tank since the beginning of December. I'm now doing a 4 gallon water change, except the last two weeks and this week I'll do a 3 gallon change. My other gallon the last couple weeks, has been slowly being given to my 2.5 gallon tank through top off water. So my new mollies can switch over to a marine environment. My water usage over the past 4 - 4 1/2 years has been minimal. Look at the current usage of 32 gallons a month, that's only 576 gallons of RO/DI for the last 18 months my 65 has been running. Yet I didn't use nearly that much. I've also filled all my tanks with tap water. Meaning, The first fill of the tank. I didn't make RO/DI to fill them.

I have a love hate relationship with RO/DI units. I simply can't stand how much waste they have. So, in my case. I collect the waste and use in my garden in the summer and make as little water as possible during the winter. Figuring out the cause of problems is better then using mass amounts of water and salt IMO. There are also other ways to remove some issues that a tank may have besides flushing 50% tank volume every other day in extreme situations. Or 40-50% every month just because we really don't know whether or not the water is bad.

This is the RO/DI unit I have. The RD-102
http://www.watergeneral.com/product01.aspx
Also, I mentioned (previous post) that I have calibration solution coming from HM digital so I can check my TDS meter. I've wondered myself if I can really trust what it's been reading. Just never bought any solution. I'm not a water expert. I just do what feels right to me. I do my best to cut through the BS and marketing hype to get my money. More often then not, that means I have to just try an idea and watch carefully.

Does anyone know of a DIY test solution for a TDS meter? I haven't searched it out yet.

jason2459
01/19/2015, 06:26 PM
Ok, so you have had up until recently very low usage mixed with using straight tap water. Nothing wrong with that as long as nothing has been harmed or wrong with the tank. And it looks like a dual DI stage.

As for DI only lasting a couple months or less can be due to heavy usage, high CO2 content, poor RO membrane rejection rate, very high source TDS, and many other factors I'm sure.

bertoni
01/19/2015, 06:29 PM
I've never heard of a DIY TDS meter. The logic behind the tests might be fairly complicated if the meters are using an AC wave form to measure resistance. That's true for testing saltwater concentrations, for example.

2_zoa
01/19/2015, 07:18 PM
I've never heard of a DIY TDS meter. The logic behind the tests might be fairly complicated if the meters are using an AC wave form to measure resistance. That's true for testing saltwater concentrations, for example.

Not a meter. A test solution to test a meter. Like the DIY refractometer calibration solution.

2_zoa
01/19/2015, 07:20 PM
Ok, so you have had up until recently very low usage mixed with using straight tap water. Nothing wrong with that as long as nothing has been harmed or wrong with the tank. And it looks like a dual DI stage.

As for DI only lasting a couple months or less can be due to heavy usage, high CO2 content, poor RO membrane rejection rate, very high source TDS, and many other factors I'm sure.

I wasn't sure if the quantity of resin I have would equal one of the 10" vertical ones. Although, I guess they are about the size of those inserts.

2_zoa
01/20/2015, 11:13 PM
I remembered that I have pen style TDS meter. So I checked my RO/DI water with it. It also says 0 TDS.

The calibration solution along with a new TDS pen by HM digital should be here Monday. I'm really curious if my meters are still accurate.

bertoni
01/21/2015, 03:54 PM
Not a meter. A test solution to test a meter. Like the DIY refractometer calibration solution.
Oops, sorry, I see. A useful calibration solution would be difficult to make without some expensive measuring equipment. It wouldn't be cost-effective unless you have free access to an analytical balance.

2_zoa
01/22/2015, 07:22 PM
Oops, sorry, I see. A useful calibration solution would be difficult to make without some expensive measuring equipment. It wouldn't be cost-effective unless you have free access to an analytical balance.

I do not. The best any scale I have access to just does grams. The solution I ordered will be here monday, so they say. I'm happy I ordered it.

Thank You

bertoni
01/22/2015, 07:49 PM
You're welcome!

2_zoa
01/23/2015, 09:37 PM
We all like early shipments. I got my handheld TDS meter and calibration solution today.

So, my TDS meter on my RO/DI unit was way off. It was reading high 600's almost 700ppm on 342ppm solution. After taking my time and making small adjustments I was able to get all my meters and sensors (Two handheld and a two sensor meter) to read within 2ppm of the solution. Oddly, to me. They still don't read really any different. My input water is still 80-85 and the output is still 0 after a couple mins of making water.

bertoni
01/23/2015, 11:03 PM
Hmm, that's strange. I would guess the meters are accurate enough for our purposes, at this point, anyway.