How often do you change out RO filters?
- Thread starter kentrob11
- Start date
Michael Mota
Member
usually once a year, but it really depends on what the tds meter reads
DrBDC
Active member
They say about 6 months on the prefilters. I'm not sure what water volume that is based on. I'm guilty of about 1 year on mine and I have a pretty high water volume. I "think" if you put a pressure gauge on the before and after of the prefilters it can aid in determining change time. But that's just for clogging up etc. Also, on the better prefilters there is a chlorine removal rating you can use to determine when it's usefulness is done. There are huge differences in the chlorine removal ratings of the different ones.
zt444a
New member
<a href=showthread.php?s=&postid=8749166#post8749166 target=_blank>Originally posted</a> by Im Lon 2
you are suppose to change the filters.
I have decided that I'm just going to buy a whole new unit it's almost cheaper.
Note to self: Don't shop where Lonnie shops....
:lol: :lol:
For the mesh and the carbon block, I think I can find them both at BFS for around $35 total.
What size mesh filters does everyone use?
Howard
DrBDC
Active member
If you're going to buy a new one, this one is supposed to be the best out there:
http://www.spectrapure.com/St_MaxCap-RO-DI.htm
http://www.spectrapure.com/St_MaxCap-RO-DI.htm
rams
ramtheory
DI when my TDS meter hits 3 - 7 I order because it will jump quick
I change my RO membrane yearly, use it upstairs for drinking water and ice cubes, sometimes earlier when TDS stays high after a quick flush
Pre-filters I have clear housing, usually a visual inspection lets me know. Depending on water consumption.
recommend the in-line TDS meter: it is always there to click on when you want to check.
I change my RO membrane yearly, use it upstairs for drinking water and ice cubes, sometimes earlier when TDS stays high after a quick flush
Pre-filters I have clear housing, usually a visual inspection lets me know. Depending on water consumption.
recommend the in-line TDS meter: it is always there to click on when you want to check.
Buckeye Hydro
.Registered Member
From the FAQ's on our website:
When should I replace my filters?
A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the useable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or both of the filters is beginning to clog.
Also be cognizant of the chlorine capacity of the carbon block. The Matrikx+1 (“Chlorine Guzzlerâ€Â) for example will remove 99% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons.
Regarding your RO membrane and DI resin, use your TDS meter to measure, record, and track the tds (expressed in parts per million) in three places:
1. Tap water
2. After the RO but before the DI
3. After the DI.
The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 parts per million (ppm). Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?
If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block filter (collectively called prefilters) do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in†port on your RO housing and you'll see its still approximately 400 ppm.
The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 90% (i.e., they reject 90% of the dissolved solids in feed water). So the purified water coming from your 100 gpd membrane would be about 40 ppm (a 90% reduction). Filmtec 75 gpd (and below) membranes produce less purified water (aka “permeateâ€Â), but have a higher rejection rate (96 to 98%). The life span of a RO membrane is dependant upon how much water you run through it, and how dirty the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the total dissolved solids (TDS) in the water coming in to the membrane, and in the purified water (permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. How do you measure TDS? Membranes also commonly produce less water as their function declines.
After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the 40 ppm water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm to 3 ppm, 5 ppm, and higher, you know that your resin needs to be replaced. Sometimes people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin “dirty†water. This will exhaust the resin quicker then would otherwise have been the case. Sometimes the problem is poor quality resin â€"œ remember that all resins are not created equal!
When should I replace my filters?
A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the useable life of these two filters is to use a pressure gauge to identify when pressure reaching the membrane starts to decline. This is your indication one or both of the filters is beginning to clog.
Also be cognizant of the chlorine capacity of the carbon block. The Matrikx+1 (“Chlorine Guzzlerâ€Â) for example will remove 99% of chlorine from 20,000 gallons of tap water presented at 1 gpm. Original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons.
Regarding your RO membrane and DI resin, use your TDS meter to measure, record, and track the tds (expressed in parts per million) in three places:
1. Tap water
2. After the RO but before the DI
3. After the DI.
The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 parts per million (ppm). Common readings are 100 to 400 ppm. So for sake of discussion, let's say your tap water reads 400 ppm. That means that for every million parts of water, you have 400 parts of dissolved solids. How do we go about getting that TDS reading down to somewhere near zero?
If you do some experimenting with your TDS meter, you'll note that your sediment filter and carbon block filter (collectively called prefilters) do very little to remove dissolved solids. So with your tap water at 400 ppm, you can measure the water at the “in†port on your RO housing and you'll see its still approximately 400 ppm.
The RO membrane is really the workhorse of the system. It removes most of the TDS, some membranes to a greater extent than others. For instance, 100 gpd Filmtec membranes have a rejection rate of 90% (i.e., they reject 90% of the dissolved solids in feed water). So the purified water coming from your 100 gpd membrane would be about 40 ppm (a 90% reduction). Filmtec 75 gpd (and below) membranes produce less purified water (aka “permeateâ€Â), but have a higher rejection rate (96 to 98%). The life span of a RO membrane is dependant upon how much water you run through it, and how dirty the water is. Membranes can function well for a year, two years, or more. To test the membrane, measure the total dissolved solids (TDS) in the water coming in to the membrane, and in the purified water (permeate) produced by the membrane. Compare that to the membrane’s advertised rejection rate, and to the same reading you recorded when the membrane was new. How do you measure TDS? Membranes also commonly produce less water as their function declines.
After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the 40 ppm water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm to 3 ppm, 5 ppm, and higher, you know that your resin needs to be replaced. Sometimes people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin “dirty†water. This will exhaust the resin quicker then would otherwise have been the case. Sometimes the problem is poor quality resin â€"œ remember that all resins are not created equal!
DrBDC
Active member
Thanks for the info. If you are changing a 3 prefilter unit, what combination size would you recommend? Here is a water quality report for our area in case that is needed:
http://129.41.243.229/awpr1/moaw/pdf/MO StLouis-web.pdf
http://129.41.243.229/awpr1/moaw/pdf/MO StLouis-web.pdf
Buckeye Hydro
.Registered Member
The thing that jumps out at me from that report is the presence of chloramine. So on a system with 3 prefilters, and assuming yu don't have substantial problems with high sediment loads:
1 mic sediment filter
catalytic GAC
0.6 micron 20,000 gallon arbon block "The Chlorine Guzzler"
Russ
1 mic sediment filter
catalytic GAC
0.6 micron 20,000 gallon arbon block "The Chlorine Guzzler"
Russ
DrBDC
Active member
Cool! I need to get online and order from you guys. I bought my 75 gpd membrane, pressure gauge, refillable di unit and resin from you and it was the best prices I found!
I just noticed you carried the Dowflake and magflake too!
One more Q, will 2 storage tanks work? I was thinking of adding the 14 gallon one onto my system which already has a 3 or 4 gallon tank. Since they are pressurized which then makes the unit shut off, I would think it would work but thought I'd ask anyway.
I just noticed you carried the Dowflake and magflake too!
One more Q, will 2 storage tanks work? I was thinking of adding the 14 gallon one onto my system which already has a 3 or 4 gallon tank. Since they are pressurized which then makes the unit shut off, I would think it would work but thought I'd ask anyway.
Similar threads
