Well water & RODI - Effecting Corals?!?

CUSE1315 · 06/30/2016, 12:33 PM

Question about water and being on a well?!

I moved a year ago. I went from 142 TDS tap (always 0 after RODI) to being in a town where I am on well water that is 300 out of the tap (always 0 after RODI).

I am having issues keeping corals (I will lose a head of euphyllia here and there).

Is there substances that may be undetectable by a 0 TDS reading that could still be in my water effecting my corals?

Reef Bass · 06/30/2016, 12:56 PM

Yes. TDS meters measure the conductivity of a solution, and so particles without ionic charge will not register.

CUSE1315 · 06/30/2016, 01:38 PM

What other substances could there be and if there is, how would I test for these? This is getting to be a frustrating situation and I would like to know if I should find another water source at this point. Thanks a lot!

Horace · 06/30/2016, 05:27 PM

Are u using DI? There is no way a RO will get 300 to 0 TDs alone. Even the best membrane will leave 1 - 2% of tds

Sent from my Nexus 6 using Tapatalk

CStrickland · 06/30/2016, 06:25 PM

I wouldn't think that's your culprit. While it's true that a good amount of the not-water that can be present in our water will not register on a tds meter, I don't see how those things could be present without also have something tag along that would raise the tds.

Think of it this way: if you have a series of screens that get finer and finer, and you pour sand through them, the only sand you will find at the end will be very very small; if you want to find out that the screens are working, you only have to look for the sand that shouldn't get through the last screen - you don't have to look for big rocks that the first screen can catch because as long as the last screen is working it's safe to assume the rest are in order. Alternatively, if you are seeing stuff get through that shouldn't pass the last screen, or the screens are clogging up really fast, you have to look more closely to find which part is out of order.

Rodi does not work this way like a screen, but the tds test tells you similar information. By looking at the very last thing that should be removed it tells you that the whole system is working properly. If the contaminants that can hide from the meter were getting into your tank, the ones it can see would also be there. So the tds meter cannot tell you how dirty the water is because if the tds is more than zero the unit isn't working and there's no way to know what else is getting past it, but it can tell you that it is clean because if the tds-raisers are kept out so are the tds-hiders. So your reading of zero tds confirms that the water you are using is pure.

Ron Reefman · 06/30/2016, 06:37 PM

Quote:

Originally Posted by Reef Bass

Yes. TDS meters measure the conductivity of a solution, and so particles without ionic charge will not register.

Could you name a few just to help educate some of us... like me.

CStrickland · 06/30/2016, 06:57 PM

Quote:

Originally Posted by Ron Reefman

Could you name a few just to help educate some of us... like me.

This might help http://reefkeeping.com/issues/2004-0...ture/index.php

Quote:

Since TDS meters are often used to test water "purity," it is important to understand what they do not detect. As conductivity meters in disguise, TDS meters will only detect mobile charged ions. They will not detect any neutral (uncharged) compounds. Such compounds include sugar, alcohol, many organics (including many pesticides and their residues), and unionized forms of silica, ammonia, and carbon dioxide. These meters also do not detect macroscopic particulates, as those are too large to move in the electric fields applied. So if you see "rusty" looking water from iron oxide particulates, that won't be measured. Neither will anything else that makes the water look cloudy. Bacteria and viruses also won't be detected.

Reef Bass · 06/30/2016, 07:03 PM

Nicely summarized CStrickland, thanks.

Ron, I hope that answers your question. I don't have much to add. Except my dismay when I learned zero TDS doesn't mean nothing in the water!

Reef Frog · 07/01/2016, 01:00 PM

Keep in mind that losing a coral head occasionally could be completely coincidental and your 0 TDS water is just fine. If you are ultra paranoid and have cash to burn, there are high level tests that can be commissioned to test for a multitude of exotic compounds. But if on the show everything else is doing well, you probably have nothing to worry about.

06/30/2016, 12:33 PM	#1
CUSE1315 Registered Member Join Date: Apr 2015 Location: Syracuse Posts: 327	Well water & RODI - Effecting Corals?!? Question about water and being on a well?! I moved a year ago. I went from 142 TDS tap (always 0 after RODI) to being in a town where I am on well water that is 300 out of the tap (always 0 after RODI). I am having issues keeping corals (I will lose a head of euphyllia here and there). Is there substances that may be undetectable by a 0 TDS reading that could still be in my water effecting my corals?

06/30/2016, 12:56 PM	#2
Reef Bass colors and textures Join Date: Jan 2004 Location: Petaluma CA Posts: 6,301	Yes. TDS meters measure the conductivity of a solution, and so particles without ionic charge will not register. __________________ The human desires for instant gratification and immediate problem resolution cannot be satisfied with this hobby. Former president and co-president of the Wine Country Reefers. Current Tank Info: 60 gallons of Scleractinia and Zoanthidae lit w/ LEDs

06/30/2016, 05:27 PM	#4
Horace Registered Member Join Date: Mar 2005 Location: Atlanta Posts: 5,009	Are u using DI? There is no way a RO will get 300 to 0 TDs alone. Even the best membrane will leave 1 - 2% of tds Sent from my Nexus 6 using Tapatalk __________________ -Horace Pinker Current Tank Info: New 180g Mixed SPS Build in progress

06/30/2016, 06:25 PM	#5
CStrickland Registered Member Join Date: Jan 2015 Location: New England, U.S. Posts: 4,595	I wouldn't think that's your culprit. While it's true that a good amount of the not-water that can be present in our water will not register on a tds meter, I don't see how those things could be present without also have something tag along that would raise the tds. Think of it this way: if you have a series of screens that get finer and finer, and you pour sand through them, the only sand you will find at the end will be very very small; if you want to find out that the screens are working, you only have to look for the sand that shouldn't get through the last screen - you don't have to look for big rocks that the first screen can catch because as long as the last screen is working it's safe to assume the rest are in order. Alternatively, if you are seeing stuff get through that shouldn't pass the last screen, or the screens are clogging up really fast, you have to look more closely to find which part is out of order. Rodi does not work this way like a screen, but the tds test tells you similar information. By looking at the very last thing that should be removed it tells you that the whole system is working properly. If the contaminants that can hide from the meter were getting into your tank, the ones it can see would also be there. So the tds meter cannot tell you how dirty the water is because if the tds is more than zero the unit isn't working and there's no way to know what else is getting past it, but it can tell you that it is clean because if the tds-raisers are kept out so are the tds-hiders. So your reading of zero tds confirms that the water you are using is pure. __________________ If you're havin tank problems I feel bad for you, son. I got 99 problems but a fish ain't one Current Tank Info: 3/2016 upgrade to 120g. Chalk bass, melanurus, firefish, starry blenny, canary blenny, lyretail anthias, engineer gobys, kole tang. Softies / LPS / NPS. <3 noob4life <3 Last edited by CStrickland; 06/30/2016 at 06:31 PM. Reason: I broke my phone screen so I can't really see what I'm typing until it posts. Turns out I make a lot of typos

06/30/2016, 07:03 PM	#8
Reef Bass colors and textures Join Date: Jan 2004 Location: Petaluma CA Posts: 6,301	Nicely summarized CStrickland, thanks. Ron, I hope that answers your question. I don't have much to add. Except my dismay when I learned zero TDS doesn't mean nothing in the water! __________________ The human desires for instant gratification and immediate problem resolution cannot be satisfied with this hobby. Former president and co-president of the Wine Country Reefers. Current Tank Info: 60 gallons of Scleractinia and Zoanthidae lit w/ LEDs Last edited by Reef Bass; 06/30/2016 at 07:28 PM.

06/30/2016, 01:38 PM	#3
CUSE1315 Registered Member Join Date: Apr 2015 Location: Syracuse Posts: 327	What other substances could there be and if there is, how would I test for these? This is getting to be a frustrating situation and I would like to know if I should find another water source at this point. Thanks a lot!

07/01/2016, 01:00 PM	#9
Reef Frog Registered Member Join Date: Feb 2013 Location: Maryland Posts: 3,121	Keep in mind that losing a coral head occasionally could be completely coincidental and your 0 TDS water is just fine. If you are ultra paranoid and have cash to burn, there are high level tests that can be commissioned to test for a multitude of exotic compounds. But if on the show everything else is doing well, you probably have nothing to worry about.