I just got a TDS meter, and my Kent HiS R/O output is already up to 25ppm? It's only a couple of months old? My tap water is around 95ppm. Is it time to change the sediment and carbon filter already, or is something else wrong? Shouldn't it be much closer to 0ppm?
New R/O putting out 25 ppm on TDS meter?
- Thread starter Pennywise
- Start date
RO rarely can get dow to "0" ppm unless your water is 2-5ppm to start with.
Check the sediment filter visually. It should not be discolored. Rather you replace the prefilters depends on your water usage. In almost all the case, it won't help the TDS reading unless they are so old that chlorine goes thru the carbon, and deteriate the RO membrane.
With that said, 25 ppm is not bad for RO. Mine is between 10ppm to 20 ppm, but I have a <brag> kickass system </brag>. Sometimes if you let the RO runs for a few minutes before taking the TDS reading, it will go down a little bit because of the membrane creep in the begining.
So relax...
Check the sediment filter visually. It should not be discolored. Rather you replace the prefilters depends on your water usage. In almost all the case, it won't help the TDS reading unless they are so old that chlorine goes thru the carbon, and deteriate the RO membrane.
With that said, 25 ppm is not bad for RO. Mine is between 10ppm to 20 ppm, but I have a <brag> kickass system </brag>. Sometimes if you let the RO runs for a few minutes before taking the TDS reading, it will go down a little bit because of the membrane creep in the begining.
So relax...
imo, something is wrong with your ro unit. with it being a few months old and assuming it is a 100gpd unit, your ro membrane should have a rejection rate of at least 90%. thus, since your source water is testing at 95ppm, a functional ro unit should result in water of 9.5ppm.
assuming you have a 50 or 75gpd unit, the rejection rate is higher, 95-98%. so you should have ro water of 2-5ppm.
assuming you have a 50 or 75gpd unit, the rejection rate is higher, 95-98%. so you should have ro water of 2-5ppm.
Check and compare the flow rates of the brine (waste) water to that of the product water. I believe tha most RO membranes require/work best with a 3.5-4.0 to 1 ratio. For example, if it takes 120 seconds to produce 1 cup of RO water, it should only take 30-34 seconds to produce a cup of waste ater. If this is not happening, then the flow restrictor (typically a small tube or orrifice) on your waste water line is messed up. FWIW, I now use an adjustabel flow restrictor so that I can check and adjust the flow rates periodically.
One more point, you will get elevated TDS readings for the first few cups of product water after the RO membrane is "turned on". So make sure that you are testing the product water after it has run a bit.
One more point, you will get elevated TDS readings for the first few cups of product water after the RO membrane is "turned on". So make sure that you are testing the product water after it has run a bit.
FWIW, my tap water typically measures out at 155-160 TDS. My 75 gpd RO membrane takes it down to 5-6 TDS - and I have so-so water pressure. Oh yea, some membranes (like hgiher gpd units) don't work as well with lower water pressures.
BTW, the guys at Aquatic Reef Systems and SpectraPure have taught me more than I ever wanted to really know about RO/DI systems. My RO/DI system has been modified several times with the help of these outfits. I am sure that either of them could be of help if you can't get your RO system squared away.
BTW, the guys at Aquatic Reef Systems and SpectraPure have taught me more than I ever wanted to really know about RO/DI systems. My RO/DI system has been modified several times with the help of these outfits. I am sure that either of them could be of help if you can't get your RO system squared away.
Okay this is a really basic (stupid) question, but someone please answer it anyway...
I am just starting to convert to Di water (that I buy from an aquarium store for 45 cents a gallon), so I know very little about it. I had been wondering if I don't have to treat it at all with Prime (like I do tap water of course), because maybe there is just a little chlorine/other stuff still in it, so a little Prime would ensure that that small amount of bad stuff wouldn't be a problem (Its just DI water, not DI/RO). When you guys talk about ppm in your Di/RO water, what specifically are you referring to? Thanks, I just need to clear this up, this discussion got me thinking about it again.
I am just starting to convert to Di water (that I buy from an aquarium store for 45 cents a gallon), so I know very little about it. I had been wondering if I don't have to treat it at all with Prime (like I do tap water of course), because maybe there is just a little chlorine/other stuff still in it, so a little Prime would ensure that that small amount of bad stuff wouldn't be a problem (Its just DI water, not DI/RO). When you guys talk about ppm in your Di/RO water, what specifically are you referring to? Thanks, I just need to clear this up, this discussion got me thinking about it again.
If it is DI, you don't need to add dechlor. in it. It is for straight tap water.
If there is chlorine in it, it is not worth the money. TDS on DI should be around "0" to 1 ppm.
TDS means total dissolved solid. In reality, it is a measurement of the ocnductivity of the water. anything that does not conduct electricity will not be detected. Chlorine ion does. Randy has an article on it on www.reefkeeping.com, take a look if you want to know more.
If there is chlorine in it, it is not worth the money. TDS on DI should be around "0" to 1 ppm.
TDS means total dissolved solid. In reality, it is a measurement of the ocnductivity of the water. anything that does not conduct electricity will not be detected. Chlorine ion does. Randy has an article on it on www.reefkeeping.com, take a look if you want to know more.
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