[mabrungard]

Good catch, Phil. My bad, I'm used to units like gpm in my day job. I've revised my post to read gpd, as intended.

With regard to Phil's system. It's virtually the same with the teeny filters. A system with the larger under-sink, 10" or 20" filters provides a longer residence time in the carbon and that significantly improves the reliability and completeness of chlorine-compound removal. Don't skimp there or you will be replacing your membrane and the carbon filter way more often than you would normally have to. There is a nice write up about what to look for when buying a RO system on the Bru'n Water Facebook page.

[Stevie]

Would adding an additional carbon filter where the sediment filter is work Martin? Is a sediment filter really needed with most municipal water supplies?

[Phil_M]

I've considered setting up a whole-house water filter...would that plus the RO carbon filter likely remove enough chloramine to keep the membrane safe?

[pfabsits]

The things to consider when purchasing an RO system are the replacement filter costs and availability. The RO membrane that does the work of removing the salts from water will last a very long time but the sediment filter and carbon filter should be replaced every 6 months.

I have used the least expensive GE model from Home depot. Two in my current house (one for my use and one for related living) and one as a replacement to a Kinetico in a previous house. I am 99.99% sure that GE does not make it (except maybe the membrane from GE Osmonics). Many suppliers that we as consumers use purchase the components from the same companies.

They will all produce water at around 30-40 uS/cm (15-20 ppm TDS) which is extremely low. It is not high purity water at 18.2 mohm (0.055 uS/cm) but that is not necessary and very costly. I believe it cost us around $1500 when we have to have a DI beds changed for the water used by R&D.

To put in perspective

Groundwater in Chicago area = 1000 uS/cm (500 ppm)
Lake Michigan = 300 uS/cm (150 ppm)

At a drinking water plant in the NW (if i remember they draw from the Clackamas River in Oregon) the EC was very low at 30-40 uS/cm. I thought the meter was reading wrong since it was so low and was close to RO water. Calibrated and checked. Sure enough that was the reading. Most likely the area is granite and there are no minerals to dissolve that would increase the EC unlike Chicago where there is a lot of limestone.


http://www.homedepot.com/p/GE-Reverse-Osmosis-Filtration-System-GXRM10RBL/202073853

HD Replacement carbon filters @ $11.50 (2 pack)
http://www.homedepot.com/p/HDX-Carbon-Household-Filter-2-Pack-HDX2CF4/205373472

HD Pleated filters @ $9.00 (2 pack)
http://www.homedepot.com/p/HDX-Pleated-Household-Filter-2-Pack-HDX2PF4/205373484?MERCH=REC-_-PIPHorizontal1_rr-_-205373472-_-205373484-_-N

More expensive GE unit that uses their twist and lock filters
http://www.homedepot.com/p/GE-Twist-and-Lock-Reverse-Osmosis-Filtration-System-PXRQ15RBL/202616787

For GE twist and lock the replacement filters are $40.
http://www.homedepot.com/s/GE%2520RO%2520filter?NCNI-5

[smkranz]

These write-ups are all great reading.  I am contemplating building a portable (mounted on a cart) system using an off-the shelf solution such as one of the above G.E. systems.

I already use a carbon filter cartridge to strip the chlorine from my municipal water supply.  It is connected to an outdoor garden hose bib.  In between uses, I drain it and let it dry.  I would use the same hose bib to supply a portable RO system.

With these RO systems, is doing the same thing I'm doing with my carbon filter (breaking them down to let them try out between uses) a good or practical thing to do?  Would it affect their useful life.  I would just be concerned about the possible growth of unwanted microbes if they sat full of water for an extended period of time between uses. 

Thanks in advance!

[Phil_M]

With these RO systems, is doing the same thing I'm doing with my carbon filter (breaking them down to let them try out between uses) a good or practical thing to do?  Would it affect their useful life.  I would just be concerned about the possible growth of unwanted microbes if they sat full of water for an extended period of time between uses. 

That concern is why I ended up mounting mine under the sink. My understanding was that it was good practice to make sure the system got used frequently, and it's a lot easier to do that when it's a permanent fixture instead of a temporary one.

[Philbrew]

Good catch, Phil. My bad, I'm used to units like gpm in my day job. I've revised my post to read gpd, as intended.

With regard to Phil's system. It's virtually the same with the teeny filters. A system with the larger under-sink, 10" or 20" filters provides a longer residence time in the carbon and that significantly improves the reliability and completeness of chlorine-compound removal. Don't skimp there or you will be replacing your membrane and the carbon filter way more often than you would normally have to. There is a nice write up about what to look for when buying a RO system on the Bru'n Water Facebook page.

Martin, would this be a good system?  https://jet.com/product/detail/6b3d404a553f4b5e812b395329dc48a1?jcmp=pla:ggl:brands_home_garden_a1:kitchen_dining_kitchen_appliances_water_filters_a1_other:na:na:na:na:na:2&code=PLA15&k_clickid=a8a6e3fb-a3e1-4f72-838a-62e84be3101a&gclid=CKPJ1KKHrMkCFUKXgQodM88NeQ  It seems like a good value.

I would be using well water through a water softener so clorine is not an issue but bacteria may be.  Would a UV source take care of that?  Any recommendations for that?

[jbadd99]

Greetings!

I was browsing the forum here in anticipation of beginning brewing myself when I ran across this thread.

I purchased a system around 6 years ago at:

http://www.purewaterclub.com/catalog/index.php?cPath=88

I've used it ever since for my saltwater aquarium.  I've changed the sediment filters twice and the RO filter and DI resin once.  I also run a TDS meter in and out.  Generally my TDS is around 40ppm going in and unless the filter is going bad it's always 0ppm out.  It took me around 2.5 years and I don't even know how many 100's of gallons out for the TDS to start creeping up.  I eventually added a booster pump and an additional RO membrane to recirculate the waste water from the first filter (increasing my yield per gallon).  I've got about $325 total in my setup.

P.S. If you use one only semi-regularly (every few days or so) you'll need to purge the output line to eliminate and TDS creep from the membrane - I added a purge valve that makes the process rather quick.

Happy brewing!

[Whiskers]

Whatever you go with, I highly recommend you go with 3/8th feed line rather than the standard 1/4, especially if you  have a run of more than a few feet.  Pressure from my well bladder tank runs between 40 and 50psi, and I have a booster pump.  The feed run to the pump is ~10'.  Was only able to get the RO pressure up to 80psi once I swapped in the 3/8''. Bear in mind mine is a 120gpd so the total throughput is a chunk higher than many other smaller systems, so the pressure drop is more significant with the greater flow.  If you've only a couple of feet, higher pressure, and a lower capacity system, 1/4'' tube is likely fine.  Just putting this out there as it took me awhile to troubleshoot my issues and the 3/8th feed solved everything.

BTW Spectrapure is a fantastic place for RO/DI equipment and information.  It's where I've bought everything over the years.