Good RODI
- Thread starter sonubhai
- Start date
- Tagged users None
For drinking water you want the RO water, not the DI water.
And no, DI water should not be run through any other filter - it is as pure as your system can make it after it comes out of the DI.
Did you get this system from ebay by chance?
Russ
ckozma
Active Member
And the reasoning behind this is that there are important minerals that your body needs in it's water, but those get stripped in the final DI phase in order to reach 0 tds. In our reef aquariums, we only want the minerals that are included with our salt mixes.
rantipole
Active Member
Anyone have any thoughts on this system: http://www.marinedepot.com/Marine_D..._Systems-Marine_Depot-MD9113-FIRORDNH-vi.html
Cheers,
rant
Cheers,
rant
OP
OP
sonubhai
Active Member
@rantipole I got this form air water ice
http://airwaterice.com/typhoon-5-stage-rodi-reefkeeper.html
Free shipping, no tax for CA. I get 0 TDS
And no issues. I am a month into my use.
http://airwaterice.com/typhoon-5-stage-rodi-reefkeeper.html
Free shipping, no tax for CA. I get 0 TDS
And no issues. I am a month into my use.
No TDS meter, no pressure gauge, no spec's on the carbon block, no brand name provided for the membrane.
Opus
2500 Club Member
I would be worried if I was getting that out of a 75gpd unit. Either something is not setup correctly or the wrong RO filter was included. That works out to almost 200gpd. What is the TDS at the faucet and after the RO membrane?
Nothing compares to Spectrapure. Low micron near absolute rated sediment and carbon block filters, specially treated and batch or hand tested high rejection rate RO membranes, custom blended in house DI resins, capillary tube flow restrictors and more for only around $125.
From our FAQ's:
A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the usable 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 more of the prefilters (all the filters that touch the water before it reaches the RO membrane) is beginning to clog.
Also be cognizant of the chlorine capacity of the carbon block. A good 0.5 micron carbon block for example will remove much of the chlorine from 20,000 gallons of tap water presented at 1 gpm. Some original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons. Remember that all the water you process, both waste water and purified water, goes through the carbon block.
Regarding your RO membrane and DI resin, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in three places: 1) tap water, 2) after the RO but before the DI, and 3) after the DI.
The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 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 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 membrane housing and you'll see it is 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 98% (i.e., they reject 98% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 8 ppm (a 98% reduction). The lifespan of an RO membrane is dependent 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 TDS in the water coming into 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. Membranes also commonly produce purified water more slowly as their function declines.
After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the TDS in the RO water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm, your resin needs to be replaced. Sometimes you'll hear people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin high TDS water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal.
Additionally, don’t forget to sanitize the entire system at least once per year, and wash and lube your housing o-rings with food-grade silicone grease every filter change.
Russ
A good rule of thumb is to replace your sediment filter and carbon block after six months. A more precise way to maximize the usable 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 more of the prefilters (all the filters that touch the water before it reaches the RO membrane) is beginning to clog.
Also be cognizant of the chlorine capacity of the carbon block. A good 0.5 micron carbon block for example will remove much of the chlorine from 20,000 gallons of tap water presented at 1 gpm. Some original equipment suppliers commonly provide carbon cartridges rated at 2,000 to 6,000 gallons. Remember that all the water you process, both waste water and purified water, goes through the carbon block.
Regarding your RO membrane and DI resin, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in three places: 1) tap water, 2) after the RO but before the DI, and 3) after the DI.
The TDS in your tap water will likely range from about 50 ppm to upwards of 1000 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 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 membrane housing and you'll see it is 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 98% (i.e., they reject 98% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 8 ppm (a 98% reduction). The lifespan of an RO membrane is dependent 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 TDS in the water coming into 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. Membranes also commonly produce purified water more slowly as their function declines.
After the RO membrane, water will flow to your DI housing. DI resin in good condition will reduce the TDS in the RO water down to 0 or 1 ppm. When the DI output starts creeping up from 0 or 1 ppm, your resin needs to be replaced. Sometimes you'll hear people complain that their DI resin didn't last very long. Often the culprit is a malfunctioning RO membrane sending the DI resin high TDS water. This will exhaust the resin quicker than would otherwise have been the case. Sometimes the problem is poor quality resin – remember that all resins are not created equal.
Additionally, don’t forget to sanitize the entire system at least once per year, and wash and lube your housing o-rings with food-grade silicone grease every filter change.
Russ
Thanks. I grabbed a few parts and routed the lines and shutoffs so I can make drinking water or aquarium water. I bought a max water unit. Im in Canada so after checking out duty and taxes ordering cross border got really expensive.
Working great so far.
ifarmer
Valuable Member
I have a brs 75g rodi system and i am not happy about it.
The pressure gauge stopped working about 10 months. The restrictor leaked after about a year.
My next system will be spectrapure
The pressure gauge stopped working about 10 months. The restrictor leaked after about a year.
My next system will be spectrapure
