blackjacktang
Active Member
I have a 5 stage RO/DI unit with a TDS meter and was wondering if the TDS meter detects chlorine. If no, then if your TDS meter reads 5ppm or lower, then can u assume the chlorine wont effect marine aquariums?
RO/DI unit Quastion
- Thread starter blackjacktang
- Start date
aquaknight
Active Member
Originally Posted by Blackjacktang
http:///forum/post/3294010
I have a 5 stage RO/DI unit with a TDS meter and was wondering if the TDS meter detects chlorine. If no, then if your TDS meter reads 5ppm or lower, then can u assume the chlorine wont effect marine aquariums?
First, are you sure your city water supply uses chlorine and not chloramines? More and more Utlities are using chloramines instead. Chlorine is easy to deal with, chloramines not so much.
If you vigorously aerate your water for 24 hrs. before using it, the chlorine will change back to a gas and evap out. Chloramines must be removed by the RO/DI unit. It simply can't be blown out. However both chlorine and chloramines are removed by the carbon stages on your RO unit. If they happen to get past, they tend to wreck havoc on the RO membrane and start to eat it up. However they wouldn't get past the DI stage, if it's working correctly. Which brings me too;
If you DI stage is letting out 5ppm, it's expired. Most recommend no more then 2ppm before replacing the DI media. In theory it is technically impossible for DI resin not to completely strip the water. If you are using one of those smaller horizontally mounted DI sections this could be a reason. It impossible to pack DI resin tight enough in a canister for a horizontal application. What happens is most of the water just channels across the top and not actually through the media. If yours is mounted horizontal, orientate it vertically. Or even better, go buy a separate 10" vertical DI section. Only around $35 w/media.
http:///forum/post/3294010
I have a 5 stage RO/DI unit with a TDS meter and was wondering if the TDS meter detects chlorine. If no, then if your TDS meter reads 5ppm or lower, then can u assume the chlorine wont effect marine aquariums?
First, are you sure your city water supply uses chlorine and not chloramines? More and more Utlities are using chloramines instead. Chlorine is easy to deal with, chloramines not so much.
If you vigorously aerate your water for 24 hrs. before using it, the chlorine will change back to a gas and evap out. Chloramines must be removed by the RO/DI unit. It simply can't be blown out. However both chlorine and chloramines are removed by the carbon stages on your RO unit. If they happen to get past, they tend to wreck havoc on the RO membrane and start to eat it up. However they wouldn't get past the DI stage, if it's working correctly. Which brings me too;
If you DI stage is letting out 5ppm, it's expired. Most recommend no more then 2ppm before replacing the DI media. In theory it is technically impossible for DI resin not to completely strip the water. If you are using one of those smaller horizontally mounted DI sections this could be a reason. It impossible to pack DI resin tight enough in a canister for a horizontal application. What happens is most of the water just channels across the top and not actually through the media. If yours is mounted horizontal, orientate it vertically. Or even better, go buy a separate 10" vertical DI section. Only around $35 w/media.
blackjacktang
Active Member
i dont know if this helps but this is what mine looks like and is mounted
aquaknight
Active Member
Yea, it appears that the DI section is the one on the very top? Mounting vertical might help achieve lower TDS.
But those horizontal DI units are small, and hold less resin then a normal 10" vertical unit. If mounting yours vertical doesn't help, I would really suggest getting a vertical unit. They are clear and have color-changing DI resin as an additional way to monitor. They also can be separated and then you'll only have to buy resin, which is cheaper then a whole new horizontal cartridge, since those don't have replaceable media.
Here is the 10" Tide DI unit from TheFilterGuys for $36.
I forgot I didn't exactly answer your original question. No, the TDS meter can not individually detect chlorine, but chlorine could be apart of that 5ppm, however unlikely.
But those horizontal DI units are small, and hold less resin then a normal 10" vertical unit. If mounting yours vertical doesn't help, I would really suggest getting a vertical unit. They are clear and have color-changing DI resin as an additional way to monitor. They also can be separated and then you'll only have to buy resin, which is cheaper then a whole new horizontal cartridge, since those don't have replaceable media.
Here is the 10" Tide DI unit from TheFilterGuys for $36.
I forgot I didn't exactly answer your original question. No, the TDS meter can not individually detect chlorine, but chlorine could be apart of that 5ppm, however unlikely.
blackjacktang
Active Member
thanks a ton, and if the TDS meter reads like 2ppm then i dont have to worry about chlorine?
aquaknight
Active Member
If you're up for some additional reading, Cranberry had a great thread about chlorine/chloramines;
https://forums.saltwaterfish.com/vb/s...RO-DI-too-much
The only way for sure to tell, would be to get a test kit and test for them. I bought one and my results are on the 2nd page in the above thread. For 2ppm, it would highly unlikely, they are getting completely past the RO/DI unit. But usually IME, once the DI starts getting to about 2ppm, it starts to climb pretty quickly. When mine hits 2ppm, I order new resin, and then at 4ppm, I replace.
And again to reitierate, it's worth knowing if you local water ulitilty uses chlorine or chloramines. Chlorine isn't hard if it gets past, just aerate. Chloramines, you basically have to dump the water and wait for new filters to arrive.
https://forums.saltwaterfish.com/vb/s...RO-DI-too-much
The only way for sure to tell, would be to get a test kit and test for them. I bought one and my results are on the 2nd page in the above thread. For 2ppm, it would highly unlikely, they are getting completely past the RO/DI unit. But usually IME, once the DI starts getting to about 2ppm, it starts to climb pretty quickly. When mine hits 2ppm, I order new resin, and then at 4ppm, I replace.
And again to reitierate, it's worth knowing if you local water ulitilty uses chlorine or chloramines. Chlorine isn't hard if it gets past, just aerate. Chloramines, you basically have to dump the water and wait for new filters to arrive.
blackjacktang
Active Member
Thanks a million!
blackjacktang
Active Member
ok, i just got my RO/DI unit wroking and its testing 1ppm wich is good, if its removing that much waste from water can i be almost shure there is no chlorine or chlorimine in the water?
aquaknight
Active Member
Yea, that should be clean enough not to worry. Just don't let the carbon prefilters go tooo long. Generally replace yearly, depending... Some time in the future it would be advantageous to pick up one of those chlorine/chloramine test kits.
Additionally, could you take TDS reading of your tap water, and the TDS of the water coming out of the RO membrane (not the waste) but before the DI stage?
Additionally, could you take TDS reading of your tap water, and the TDS of the water coming out of the RO membrane (not the waste) but before the DI stage?
blackjacktang
Active Member
im assuming the when you take a sample of water that is before the di stage it doesent trickle and no drain comes out. If this is wrong then i took water from the wrong spot. i got the water from the tube RITE before it goes into the DI stage, i got a reading of 131ppm
and since the water is at 1ppm wen its gone all the way threw i can use it for my fish tank?
and since the water is at 1ppm wen its gone all the way threw i can use it for my fish tank?
aquaknight
Active Member
Ya, you either took the reading from the wrong line, the unit is plumbed incorrectly, or the RO membrane is compromised. Oh, TDS meter could be broken as well.
The way an RO membrane works, is by rejection. This will answer your other thread about reusing the waste waste, and why that won't work. All commonly available RO membranes have a rejection rate of between 90%-99% percent. Meaning 90%-99% of the TDS that comes in from your tap, gets 'rejected' or sent out the waste line. If you have a tap water TDS of say 400, and an RO membrane with a rejection rate of 95%, 380 of the original TDS will be sent out the waste and only 20 TDS to the DI section for final cleaning. There is really no way an RO membrane would be letting 131 TDS out.
The way an RO membrane works, is by rejection. This will answer your other thread about reusing the waste waste, and why that won't work. All commonly available RO membranes have a rejection rate of between 90%-99% percent. Meaning 90%-99% of the TDS that comes in from your tap, gets 'rejected' or sent out the waste line. If you have a tap water TDS of say 400, and an RO membrane with a rejection rate of 95%, 380 of the original TDS will be sent out the waste and only 20 TDS to the DI section for final cleaning. There is really no way an RO membrane would be letting 131 TDS out.
blackjacktang
Active Member
yea im not shure i took it from the rite line, were should i take it from?
aquaknight
Active Member
Originally Posted by Blackjacktang
http:///forum/post/3295416
yea im not shure i took it from the rite line, were should i take it from?
Right before the DI stage. The DI stage is the one on the very top. The RO membrane is the bigger sideways one, that has 3 lines to/from it. One side only has 1 connection. That's the In line, coming from the prefilters on the bottom (the 3 vertical ones). The other side has 2. The one in the dead center is the Out, that goes to the DI stage, and the other one that's offset is the waste line.
http:///forum/post/3295416
yea im not shure i took it from the rite line, were should i take it from?
Right before the DI stage. The DI stage is the one on the very top. The RO membrane is the bigger sideways one, that has 3 lines to/from it. One side only has 1 connection. That's the In line, coming from the prefilters on the bottom (the 3 vertical ones). The other side has 2. The one in the dead center is the Out, that goes to the DI stage, and the other one that's offset is the waste line.
blackjacktang
Active Member
ooohh i was testing it right after the 3 veritcal ones, so i test it right before the last, top one? (sorry for all the quastions)
aquaknight
Active Member
Yep. Go ahead and test your tap water as well, for a comparison.
blackjacktang
Active Member
tap water - 163ppm
Water before DI stage, 2ppm
Water after both RO and DI, 1ppm
Water before DI stage, 2ppm
Water after both RO and DI, 1ppm
aquaknight
Active Member
Seems like all is well. Good to go
blackjacktang
Active Member
yay so im guessing i can use it in my tank now rite? last qaustion. promised lol ur the man
aquaknight
Active Member
Yep, should be safe it use. You bought it new, correct?
blackjacktang
Active Member
correctomondo