Over doing the RO/DI

[Basile]

I'm having trouble choosing a RO/DI unit, its not a money issue its a practicle issue. I see 3-4-5-6-7 stage unit now. And some 7 stage unit are cheaper that than a 4 stage unit. So i'm perplex as what use is a 7 stage can actually provide than a 4 can't. To me its seems a waste of filters or an unecessary expense. Any advice on whats really important and whats not, because i'm lost, lol. Thanks for your time.

[scuba ken]

I'm having trouble choosing a RO/DI unit, its not a money issue its a practicle issue. I see 3-4-5-6-7 stage unit now. And some 7 stage unit are cheaper that than a 4 stage unit. So i'm perplex as what use is a 7 stage can actually provide than a 4 can't. To me its seems a waste of filters or an unecessary expense. Any advice on whats really important and whats not, because i'm lost, lol. Thanks for your time.

7 all the way for me, more is better.

Mud beaver ?

[Cal_stir]

I run 10 stages, dual membranes, 1 poly and 2 carbons pre-filter, and a booster pump, makes water fast.
My water is 280 ppm out of the tap though, I would base my decision on what the water quality is in your area and whether your municipality is using chloramine as a disinfectant.

[Basile]

7 all the way for me, more is better.

Mud beaver ?

I run 10 stages, dual membranes, 1 poly and 2 carbons pre-filter, and a booster pump, makes water fast.
My water is 280 ppm out of the tap though, I would base my decision on what the water quality is in your area and whether your municipality is using chloramine as a disinfectant.

I think you've just hit the nail right on the head, water quality in regions. Are water quality in my region is very good, no extra salts, or metals, no gas, no pollutions of any kind. Minimal use of chlorine. So regular RO/DI should suffice. Right now i'm looking at a MaxCap 90GPD RODI w/ dual tds, ASO and membrane flush by Spectrapure and it seems to fullfill that role with plenty of stages and options and at $300 it aint cheap, lol!

[Evilweevil]

0 ppm is 0 ppm as stupid as that sounds its the same 0 out of a 4 stage as a 0 from a ten stage although the d/I resin will probably last long on a ten stage unit but in the long run those filters cost you money also ....

I have a puratek system and highly recommend it ,simple and comes with all the bells and whistles http://www.jlaquatics.com/product/vt-ro100di/Vertex+Puratek+Reverse+Osmosis+Deionization+(RO+DI )+Filter+-+100GPD.html

[Cal_stir]

0 ppm is 0 ppm as stupid as that sounds its the same 0 out of a 4 stage as a 0 from a ten stage although the d/I resin will probably last long on a ten stage unit but in the long run those filters cost you money also ....

I have a puratek system and highly recommend it ,simple and comes with all the bells and whistles http://www.jlaquatics.com/product/vt-ro100di/Vertex+Puratek+Reverse+Osmosis+Deionization+(RO+DI )+Filter+-+100GPD.html

Stupid as it sounds I started with 5 stages and was changing filters every couple months and was making water slowly, by adding pre-filter and DI stages and an extra membrane and booster pump my filters last 6 months and I make water really fast which is more efficient, stupid as it sounds.

[daplatapus]

I have to agree with some of the above. If I had to buy another unit, knowing what I know now, I'd purchase a tds meter and test my water first, then decide what I need. I ended up buying a 4 stage with 2 stage DI unit thinking I should go big or go home. Turns out my city water comes in at 50-60 ppm. I'm reading 0 tds after my RO so my DI is pretty much useless.
Check what you have for tds first before you buy, would be my suggestion. Take into account too if where you live has a history of bad water I'm the spring and make your decision from there.

[Evilweevil]

I wasn't taking a pot shot at you simmer down lol
Yes my first ro/di unit didn't last long either just a simple unit 4 stages no booster pump I don't think I got 4months out of it so I bought the new puratek with the booster pump and its been over 6months and a lot of water thru it and still going strong ..... I would recommend buying one with a booster pump though as it helps with giving the proper pressure for the filters

[Cal_stir]

I run 10 stages because I have to not because I want to, my water is 280 ppm out of the tap, like daplatapus said, if your water is less than 50 ppm then a simple 3 or 4 stage unit would suffice.

[Evilweevil]

My water is also up there t 250 something and yet it still comes out at zero and its the same zero thru my 5 stages as your 10 I am sure your system is great though an may last longer but for me and simplicity I will stick with the puratek or something simple like that

[Basile]

Well i think i found my guy; http://www.reefsupplies.ca/online-store/MaxCap-90GPD-RODI-w-dual-tds-ASO-and-membrane-flush-by-Spectrapure.html because we have excellent pressure here in the capital, good water no contaminants, i'll verify with city official whats the water purifying methods and that it. :biggrin:thansks for your input.

[Cal_stir]

Well i think i found my guy; http://www.reefsupplies.ca/online-store/MaxCap-90GPD-RODI-w-dual-tds-ASO-and-membrane-flush-by-Spectrapure.html because we have excellent pressure here in the capital, good water no contaminants, i'll verify with city official whats the water purifying methods and that it. :biggrin:thansks for your input.

Knowing our government you probably have bottled water coming out of your tap, lol.

[Basile]

Knowing our government you probably have bottled water coming out of your tap, lol.

LOL Knowing yours i hate to see where it comes from LOL...:mrgreen:

[Cal_stir]

I think mine comes from the toilet.

[Basile]

I think mine comes from the toilet.

LOL peace bro
:biggrin:

[mike31154]

A water report from your provider is definitely a great place to start prior to deciding how many stages you may need. Should be available online, it's pretty much mandatory for them to make monthly & annual reports publicly accessible. These should not only show TDS, but also 'what' those dissolved solids are, i.e. broken down into the elements & minerals in your water. You'd be surprised at some of the stuff still coming down the line. There are fairly strict guidelines these days but it largely depends on the source as to what your TDS will consist of. The report should provide a comparison between what you get out of the tap vs what's considered safe with regard to potentially harmful elements in potable water.

Verifying the water pressure with a gauge is also not a bad idea. Anything over 60 psi is a good number, lower may indicate the requirement for a booster pump. Before spending the $$s on a booster pump, check your house for a pressure regulating (reducing?) valve (PRV). Most jurisdictions these days require them by code to protect your plumbing from surges. I've tweaked the PRV in my house to provide close to 110 psi from the standard 60-70. Why pay for a booster pump when the city already provides a higher pressure & you're paying for that through your water bill? You need to ensure your plumbing is in good shape though & there will be a higher risk of a leak. I think most plumbing is rated to well over 200 psi, but I'm not a plumber, so don't take my word on that!

While the focus here has been on the number of stages, how you run your RO/DI can have a significant impact on filter life and the quality of product water. Adding more filters is not always the answer, since each stage you add before the RO membrane will cut down the water pressure to it & slow down the output. Quality of filters can vary, so watch what you buy there, especially when it comes to carbon blocks. On most days, my source TDS is around 180 and my 75 gpd membrane, which is still the original from April 2009, will produce RO water TDS of 1 within 5-10 minutes after I fire the system up. During the winter, with colder water coming in, it will actually produce 0 TDS water. Speaking of membranes, a 75 gpd may be preferable over a 90 gpd since it's ability to lower TDS is better. This is worth considering especially in our application, where a DI stage follows the membrane. The lower you can get the TDS before it reaches the DI stage, the longer the media will last. Down side is that it takes a tad longer to produce water. But when you think about it, the difference between 90 & 70 is not all that much in the big picture, when you're looking to save $$s on DI media. The two costliest components to replace on your system are the RO membrane & DI media, so the more you can do to make those last, the more you save.

I currently run 5 stages. My system came with two carbon stages which I found to be overkill since my water is treated with chlorine, not chloramine. Generally if your source water is chloramine treated, 2 carbon stages are required to protect the membrane. I replaced the extra carbon stage with a 1 micron sediment filter. So now I have a 5 micron sediment, 1 micron sediment, 0.5 micron carbon block, 75 gpd RO membrane & DI stage.

My DI media went from April 2009 to June 2012 before TDS finally went from 0 to 1. I keep track of water through my system on an Excel spreadsheet & figure I put about 15000 gallons through in that time. The calculation includes pure water produced, plus an estimate of waste water based on a 1:4 pure vs waste ratio to give me total gallons throughput. Since the carbon block was rated for 20,000 gallons, I decided to change it at the same time, even though a chlorine test with a swimming pool test strip showed no traces of chlorine after the carbon stage. I figured at 15000 gallons, the carbon stage owed me nothing.

Some info on what I think has helped maximize life of filters/DI media based on own experience follows:

1. I manually flush the RO membrane for about a minute before & after each production cycle. The first 1/2 gallon of RO water produced goes into a waste bucket, since it takes a good 2-3 minutes for the TDS to get down to 2 then 1. It also allows the TDS after the sediment filters to stabilize. Not long ago, I added a second dual TDS meter allowing me to compare source TDS to TDS after the sediment filters. I found that on start up, TDS after the sediment filters is actually higher than the source TDS. I attribute this to junk dissolving back into solution in the cartridge housings while the system sits idle. Once fired back up it takes a few minutes for TDS after sediment filters to drop a couple of points below source TDS. During this time, the RO membrane is dealing with higher TDS and if it's feeding the DI stage, it will be working harder. Lesson here is to produce a few gallons of RO for use around the house before opening the valve to the DI stage;

2. I generally produce a minimum of 6 gallons per session. Most of the time I make more, starting with 6 gallons of RO, then 7 to 25 gallons of DI. I never feed the DI stage until I've produced 6 gallons of RO water. This ensures the TDS out of the membrane is as low as possible, usually 1 or 0 before the DI needs to go to work. Short production cycles will definitely be harder on your filters and you'll get pretty crappy production water for the first few minutes for the reasons highlighted in 1. above. A heads up for those folks who have their system plumbed directly to their ATO & allow it to be controlled by automatic shutoff switch.

Other things worth noting after running the system over the years is that I don't trust the auto shutoff valve (ASO). I'm actually considering removing the thing as it will simplify the plumbing & probably make the RO membrane more efficient with one less restricting component. I tried using the float valve in my NSW make up container when the system was new but the waste water would always continue to run after the float valve closed. Played around with the ASO & considered getting a new one, but gave up on that idea since I'm just too nervous about the reliability of the device. I have no drain in my basement floor, so chance of a flood due to an iffy little device is enough for me to be content without the automation. I'm always at home when I produce water & use the timer on my oven as a reminder to check on things periodically. I've also installed a water detector on the floor & it's saved my bacon a couple of times.

It's useful to have clear housings for your sediment filters as they provide a visual indication of their condition. I've read that a vertical DI stage is better than a horizontal one, but can't verify that from personal experience. My DI stage is vertical & has a clear housing. The initial batch of DI media was colour changing so I guess a clear housing is useful there, although the DI media I have in there now is not colour changing. I'll rely on my TDS meter to tell me when it's exhausted. Carbon block also has a clear housing, but that's probably not required - I can't think of any useful visual indicator for this stage. Difference in price between the white & clear housings is not a deal breaker, so if in doubt, clear is good I suppose. I think the white ones may be more robust.

So yeah, get a water report, check your water pressure & order away based on that!

[Basile]

A water report from your provider is definitely a great place to start prior to deciding how many stages you may need. Should be available online, it's pretty much mandatory for them to make monthly & annual reports publicly accessible. These should not only show TDS, but also 'what' those dissolved solids are, i.e. broken down into the elements & minerals in your water. You'd be surprised at some of the stuff still coming down the line. There are fairly strict guidelines these days but it largely depends on the source as to what your TDS will consist of. The report should provide a comparison between what you get out of the tap vs what's considered safe with regard to potentially harmful elements in potable water.

Verifying the water pressure with a gauge is also not a bad idea. Anything over 60 psi is a good number, lower may indicate the requirement for a booster pump. Before spending the $$s on a booster pump, check your house for a pressure regulating (reducing?) valve (PRV). Most jurisdictions these days require them by code to protect your plumbing from surges. I've tweaked the PRV in my house to provide close to 110 psi from the standard 60-70. Why pay for a booster pump when the city already provides a higher pressure & you're paying for that through your water bill? You need to ensure your plumbing is in good shape though & there will be a higher risk of a leak. I think most plumbing is rated to well over 200 psi, but I'm not a plumber, so don't take my word on that!

While the focus here has been on the number of stages, how you run your RO/DI can have a significant impact on filter life and the quality of product water. Adding more filters is not always the answer, since each stage you add before the RO membrane will cut down the water pressure to it & slow down the output. Quality of filters can vary, so watch what you buy there, especially when it comes to carbon blocks. On most days, my source TDS is around 180 and my 75 gpd membrane, which is still the original from April 2009, will produce RO water TDS of 1 within 5-10 minutes after I fire the system up. During the winter, with colder water coming in, it will actually produce 0 TDS water. Speaking of membranes, a 75 gpd may be preferable over a 90 gpd since it's ability to lower TDS is better. This is worth considering especially in our application, where a DI stage follows the membrane. The lower you can get the TDS before it reaches the DI stage, the longer the media will last. Down side is that it takes a tad longer to produce water. But when you think about it, the difference between 90 & 70 is not all that much in the big picture, when you're looking to save $$s on DI media. The two costliest components to replace on your system are the RO membrane & DI media, so the more you can do to make those last, the more you save.

I currently run 5 stages. My system came with two carbon stages which I found to be overkill since my water is treated with chlorine, not chloramine. Generally if your source water is chloramine treated, 2 carbon stages are required to protect the membrane. I replaced the extra carbon stage with a 1 micron sediment filter. So now I have a 5 micron sediment, 1 micron sediment, 0.5 micron carbon block, 75 gpd membrane & DI stage.

My DI media went from April 2009 to June 2012 before TDS finally went from 0 to 1. I keep track of water through my system on an Excel spreadsheet & figure I put about 15000 gallons through in that time. The calculation includes pure water produced, plus an estimate of waste water based on a 1:4 pure vs waste ratio to give me total gallons throughput. Since the carbon block was rated for 20,000 gallons, I decided to change it at the same time, even though a chlorine test with a swimming pool test strip showed no traces of chlorine after the carbon stage. I figured at 15000 gallons, the carbon stage owed me nothing.

Some info on what I think has helped maximize life of filters/DI media based on own experience follows:

1. I manually flush the membrane for about a minute before & after each production cycle. The first 1/2 gallon of RO water produced goes into a waste bucket, since it takes a good 2-3 minutes for the TDS to get down to 2 then 1. It also allows the TDS after the sediment filters to stabilize. Not long ago, I added a second dual TDS meter allowing me to compare source TDS to TDS after the sediment filters. I found that on start up, TDS after the sediment filters is actually higher than the source TDS. I attribute this to junk dissolving back into solution in the cartridge housings while the system sits idle. Once fired back up it takes a few minutes for TDS after sediment filters to drop a couple of points below source TDS. During this time, your RO membrane is dealing with higher TDS and if you're feeding the DI stage, it will be working harder. Lesson here is to produce a few gallons of RO for use around the house before opening the valve to the DI stage;

2. I generally produce a minimum of 6 gallons per session. Most of the time I make more, starting with 6 gallons of RO, then 7 to 25 gallons of DI. I never feed the DI stage until I've produced 6 gallons of RO water. This ensures the TDS out of the membrane is as low as possible, usually 1 or 0 before the DI needs to go to work. Short production cycles will definitely be harder on your filters and you'll get pretty crappy production water for the first few minutes for the reasons highlighted in 1. above. A heads up for those folks who have their system plumbed directly to their ATO & allow it to be controlled by a float switch.

Other things worth noting after running the system over the years is that I don't trust the auto shutoff valve (ASO). I'm actually considering removing the thing as it will simplify the plumbing & probably make the RO membrane more efficient with one less restricting component. I tried using the float valve in my NSW make up container when the system was new but the waste water would always continue to run after the float valve closed. Played around with the ASO & considered getting a new one, but gave up on that idea since I'm just too nervous about the reliability of the device. I have no drain in my basement floor, so chance of a flood due to an iffy little device is enough for me to be content without the automation. I'm always at home when I produce water & use the timer on my oven as a reminder to check on things periodically. I've also installed a water detector on the floor & it's saved my bacon a couple of times.

It's useful to have clear housings for your sediment filters as they provide a visual indication of their condition. I've read that a vertical DI stage is better than a horizontal one, but can't verify that from personal experience. My DI stage is vertical & has a clear housing. The initial batch of DI media was colour changing so I guess a clear housing is useful there, although the DI media I have in there now is not colour changing. I'll rely on my TDS meter to tell me when it's exhausted. Carbon block also has a clear housing, but that's probably not required - I can't think of any useful visual indicator for this stage. Difference in price between the white & clear housings is not a deal breaker, so if in doubt, clear is good I suppose. I think the white ones may be more robust.

So yeah, get a water report, check your water pressure & order away based on that!

LOL yes i hear ya with the float valve. I plan on using one however . My system being servicing a 5 G space in my sump with a floating valve will be shut off when i leave home with a ball valve. the other 30G mixing bucket will also be shut off by that valve no water will be produced when i'm not there. Besides i work at home and when i go to bed they'll also be shut off by that simple valve. Both inspected in my routine daily inspection along with my 2 herbie drains 2minutes tops. Its shorter than a bowel movement....

[MarieH]

I live in Verdun, suburb of Montreal, my water is 148 tds from the tap. I got an aquasafe for price point and free ship. I bought the faucet adapter because I'm an apartment dweller. Tds is 000 after 7 stages. I don't mind shelling out for the resins once a year. I just find all the cartridges piled up together a bit of a bulky bother but the water is good and I think if there's more stages you can go longer between resins?

[Basile]

I was going to take max Cap spectrapure but the Vertex for $20 more as total automatic flush a booster pump and opperated by itself plug and watch is about it, so i'm going with that 100gph 4 stage.Thanks guys for your input.

[gregzz4]

Basile, what's your tapwater TDS ?

[mike31154]

Basile, what's your tapwater TDS ?

Yes, this & what's your water pressure? You may not need a booster pump. Why complicate matters? For less than $20 you should be able to score a water pressure gauge & handheld TDS meters are also available these days for about $10, usually in the recreational vehicle department of WalMerde or Crappy Tire. Do a little research on your source water before you buy & you can save money, keep things simple. More automation is not necessarily better. Keep in mind that every time you flush your membrane, water is still flowing through your carbon stage, so its chlorine removing capacity is being depleted at a faster rate. I'm still on my original membrane after over 4 years using a manual flush of a minute or so before & after production. Not a big chore.

Something I forgot to mention in my earlier post is that I've noticed after every flush cycle, the TDS out of the membrane creeps up several points until it settles in again. So frequent auto flushes are going to be hard on your DI stage.

[gregzz4]

WalMerde
:mrgreen:

[mike31154]

Tds is 000 after 7 stages. I don't mind shelling out for the resins once a year. I just find all the cartridges piled up together a bit of a bulky bother but the water is good and I think if there's more stages you can go longer between resins?

While it does seem logical that more stages are better, it really depends on each user's source water. You need to consider TDS, pressure, temperature and other contaminants, that is 'non dissolved solids', or sediment. TDS means 'dissolved solids' and the only thing in your system that will remove them is the RO membrane. Adding a bunch more sediment stages before your carbon block & membrane will do nothing but add bulk (which you find a bother) to your set up. It will also reduce the pressure at the RO membrane resulting in slower pure water production.

If you're on a well with low water pressure & a pile of iron & other sediment, then yeah, get a booster pump & maybe add a sediment stage. Alternatively, simply change out the sediment stage more often, it's the cheapest component to buy and with a clear filter housing you'll have a good visual when it starts getting real funky.

If you're on city water treated with chlorine, TDS below 200 & water pressure of 60 psi or better, you can easily get by with a 4 stage unit. 1 sediment, 1 carbon block, RO membrane & DI stage. If money is no object, knock yourself out :). Changing DI more often is not going to break the bank, but I've only done it once & it was a fiddly affair.

[mike31154]

:mrgreen:

He, yeah I can't take credit for that one. One of my dear Quebec friends blurted that out years ago. I cracked up too. Very apropos, however, I do find myself shopping there from time to time.

[Basile]

GRRRRRRRRR i whish i'd known these little details before comitting, the price of learning :surprise: , but the deed is done. I belong to a club and we meet regulary and they all had one so i signed up for one we're all in the same city and these guys know more about this than me. I'm not new to the hobby , but part of it is chineese to me . Anything revolving around plumbing is off my scanner, now i know the price of it. I've been out of the hobby to long too and things are happening very fast now, the tanks are arriving in 3 weeks from Concept Aquariums. Thanks guys for the info i'll munch on that for a while . I thought this was going to be an easy buy it appears not, LOL food for thoughts.....their's was no answer yesterday anywhere to find out about TDS and to my other questions.

[Evilweevil]

You will be really happy with that puratek system it works really well and it's plug and play nice and simple

[Spyd]

I agree. Puratek are nice units and they have everything you need all ready installed. I run 5 stages on my unit as I have added an extra di just because I had it kicking around. Can't beat the 1:1 good water to waste water ratio either.

I find my filters last for a good 6 months. I installed a chlorine / chloramine whole home filter and it is awesome!! No chlorine or chloramines in any of my household water and it lasts 6 - 7 years before I need to get the media replaced. It helps out my RO/DI unit big time as it has a lot less work to do and saves a lot of money in exhausting filters and membranes as well. Worth every penny!!!!

[mike31154]

GRRRRRRRRR i whish i'd known these little details before comitting, the price of learning :surprise: , but the deed is done. I belong to a club and we meet regulary and they all had one so i signed up for one we're all in the same city and these guys know more about this than me. I'm not new to the hobby , but part of it is chineese to me . Anything revolving around plumbing is off my scanner, now i know the price of it. I've been out of the hobby to long too and things are happening very fast now, the tanks are arriving in 3 weeks from Concept Aquariums. Thanks guys for the info i'll munch on that for a while . I thought this was going to be an easy buy it appears not, LOL food for thoughts.....their's was no answer yesterday anywhere to find out about TDS and to my other questions.

Don't sweat it, you'll get a very good system & can omit any parts not required once you get the feel for it. Generally you can't go wrong with advice provided by a local club. I checked the Ville de Gatineau site & was unable to find any water quality reports either. All I could come up with is that they subscribe to the Programme d'excellence en eau potable (program for excellence in drinking water), which surpasses the provincial standards required under the Regulation respecting the quality of drinking water. This doesn't help when you're looking for TDS numbers or what's still in it.

http://www.gatineau.ca/page.asp?p=environnement/eau_potable/qualite_eau_potable

In Vernon, I have access to Annual Water Reports which have all the good info on TDS etc. There are also monthly reports available.

http://www.rdno.ca/docs/2013_wq_north_kal.pdf

[Basile]

Thanks guys your a great bunch. :mrgreen: