In an attempt to better my brewing I thought I'd use my home RO system. It was completely re serviced last year basically all the guts are brand new, and the water comes from our softener into the RO system up to a spicket on the side of the sink. It was suggested I test the ph and alkalinity with aquarium ph test strips so I did that today and the ph was 6.2 and the alkalinity was 40 with a hardness of 25. Why Arecthe alkalinity and hardness so high? I was under the impression it should really be around zero. I have really hard ground water running through the softener. Before the softener I'd get all kinds of calcification, and lime buildup around my faucets that would green when oxidized so I'm guessing my plain ground water is really really hard. Any ideas on how to improve the RO numbers if possible.
My home RO system is kicking out highly alkaline water
- Thread starter olotti
- Start date
Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:
check the manufacturers specs for your unit. i'd be surprised if they stated exact numbers like "our product gives you water at pH 6.0 and alkalinity of 10"...
more likely they'll say how many ppm of each ion or soluble that the filter removes, i.e. "removes up to 500ppm hardness, 95% TDS, 100 ppm chlorine/chloramines," etc.
maybe your water is naturally full of TDS and super hard, and the filter is actually doing an amazing job. cant say without knowing the starting point. you have a municipal/county water report? i'd assume so since lansing is pretty big town.
more likely they'll say how many ppm of each ion or soluble that the filter removes, i.e. "removes up to 500ppm hardness, 95% TDS, 100 ppm chlorine/chloramines," etc.
maybe your water is naturally full of TDS and super hard, and the filter is actually doing an amazing job. cant say without knowing the starting point. you have a municipal/county water report? i'd assume so since lansing is pretty big town.
olotti
Well-Known Member
I've never had a city water report, I know I should, but I know it's really really hard, like it's messed up shutoff valves and faucets due to calcification and oxidation. There is still even a little residue even using the softener system.
If your softener is working correctly and there isn't a bypass or blending with the raw water, the water feeding the RO unit should have zero hardness. The alkalinity you report is not that high, but is higher than expected.
One important fact about RO membranes is that they have to hydrate and their performance does improve after a short period. Has the system run long before your test?
Test strips are not very accurate and may be leading you to a false conclusion. A more accurate assessment of RO system performance is to measure the treated water TDS. That should be well below 50 ppm for a well operating system. A TDS meter is cheap and reliable. Get one.
One important fact about RO membranes is that they have to hydrate and their performance does improve after a short period. Has the system run long before your test?
Test strips are not very accurate and may be leading you to a false conclusion. A more accurate assessment of RO system performance is to measure the treated water TDS. That should be well below 50 ppm for a well operating system. A TDS meter is cheap and reliable. Get one.
olotti
Well-Known Member
This is all I could find for my city's water report from 2014. The water is drawn off a well then sent through the city's filtration system from what I could gather in the report.
Cal carbonate- 376
Chloride- 30
Iron- .25
Manganese- .02
Sodium- 23
Sulfate- 67
I know you said strips are inaccurate but I decided to try it again today and the alkalinity was at zero now but the hardness was still prob 20-25 per the color chart.
olotti
Well-Known Member
Also the RO system doesn't get used a lot, my wife never uses it and I mainly uses for coffee so it sit s for periods at a time, could this lead to it being less efficient. i do notice when I drink it it has a taste/smell of what I would describe as like new rubber, like if you were to pull new rubber gaskets or washers out of a bag, so I don't prefer to use it for drinking water. What could this be from?
- Joined
- Dec 17, 2013
- Messages
- 806
- Reaction score
- 345
"Hardness is 25" - is that reading in ppm or gpg?
Are you letting the RO water run for a few minutes before testing the water?
Are you testing water out of the pressure tank or directly from the RO membrane output?
Are you letting the RO water run for a few minutes before testing the water?
Are you testing water out of the pressure tank or directly from the RO membrane output?
olotti
Well-Known Member
Ppm and yes I let it run from the spigot for a few minutes es. I just. Realized yesterday that my ro system bypasses my water softener, I thought it went into the softener first, and we have really really hard water here so I'm not surprised the hardness is still at 25.
- Joined
- Dec 17, 2013
- Messages
- 806
- Reaction score
- 345
The TDS right out of the RO membrane will be lower than the TDS in a full pressure tank.
My RO system at home produces water in the single digit PPMs.
If your water taste funny like rubber then it may need some or all the filters replaced. The RO membrane on mine is supposed to be changed every 2 years but after a year my water started tasting funny. replaced all the filters except the RO membrane cause i didn't think it was it. Still had the funny taste and it only went away after i replaced the membrane filter. Also keep in mind some of the filters need to be replaced roughly every 6 months, not all get replaced at the same time.
If your water taste funny like rubber then it may need some or all the filters replaced. The RO membrane on mine is supposed to be changed every 2 years but after a year my water started tasting funny. replaced all the filters except the RO membrane cause i didn't think it was it. Still had the funny taste and it only went away after i replaced the membrane filter. Also keep in mind some of the filters need to be replaced roughly every 6 months, not all get replaced at the same time.
- Joined
- Dec 17, 2013
- Messages
- 806
- Reaction score
- 345
This is from our FAQ's page, and may be helpful. I edited it to remove discussion of the DI stage, which won't be something needed for brewing. This applies to the residential scale RO systems many use.
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. Replace a carbon block when it reaches about half of its stated chlorine capacity.
Regarding your RO membrane, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in two places: 1) tap water, 2) after the RO but before the pressure tank (if any). This should be measured without any backpressure on the membrane.
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.
If you do some experimenting with a 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 96% (i.e., they reject 96% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 16 ppm (a 96% reduction). Filmtec 75 gpd (and below) membranes produce purified water (a.k.a. permeate) more slowly, but have a higher rejection rate (96 to 99%).
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 membranes 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.
On most RO systems with a pressurized storage tank, you'll also find a "taste and odor" filter between the tank and the faucet. This is a filter containing GAC, and should be changed periodically as well. When you notice an off taste in the water from the tank, this is a good place to start.
Additionally, dont 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. Replace a carbon block when it reaches about half of its stated chlorine capacity.
Regarding your RO membrane, use your total dissolved solids (TDS) meter to measure, record, and track the TDS (expressed in parts per million [ppm]) in two places: 1) tap water, 2) after the RO but before the pressure tank (if any). This should be measured without any backpressure on the membrane.
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.
If you do some experimenting with a 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 96% (i.e., they reject 96% of the dissolved solids in the feed water). So the purified water coming from your 100 gpd membrane would be about 16 ppm (a 96% reduction). Filmtec 75 gpd (and below) membranes produce purified water (a.k.a. permeate) more slowly, but have a higher rejection rate (96 to 99%).
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 membranes 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.
On most RO systems with a pressurized storage tank, you'll also find a "taste and odor" filter between the tank and the faucet. This is a filter containing GAC, and should be changed periodically as well. When you notice an off taste in the water from the tank, this is a good place to start.
Additionally, dont 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
