SO what is in your ro/di that the TDS....
- Thread starter Jaycen B.
- Start date
Taken from the Spectrapure website:
<span style="font-family: Arial, Helvetica, sans-serif"><span style="font-size: 14px"><u>"ZERO TDS.. IS IT REAL</u></span></span> <span style="font-family: Arial, Helvetica, sans-serif">I thought I would comment on the common misnomer "ZERO TDS". Persons stating ZERO TDS I assume are referring to Zero Indicated TDS. What's the difference you ask? Well, quite a bit when you are really talking about ultra pure water. Ultra pure water is about 18.2 mohms or about 0.05 micro-siemens. Most Reefers are after such ultra pure water in our experience. Thus, if there were such a thing as "ZERO TDS", it might be more appropriately measured around 0.05 micro siemens. Unfortunately, most (not all) inexpensive TDS meters can resolve at best about 5 micro seimens. That is several decades less sensitivity than required to be stating so called "ZERO TDS".
While 5 micro siemens conductivity (at an affordable price and rugged instrument easily operated and maintained) is very reasonable for for break-through detection to signal cartridge replacement required, it is clearly not sufficient to measure or crow about having "ZERO TDS" . Thus, postings where one has "measured" a system or component performance and state they have "ZERO TDS" should be careful to quantify the accuracy of the instrument they are using to make such a claim. Hopefully this will shed some light on... zero is not always zero."</span>
<span style="font-family: Arial, Helvetica, sans-serif"><span style="font-size: 14px"><u>"ZERO TDS.. IS IT REAL</u></span></span> <span style="font-family: Arial, Helvetica, sans-serif">I thought I would comment on the common misnomer "ZERO TDS". Persons stating ZERO TDS I assume are referring to Zero Indicated TDS. What's the difference you ask? Well, quite a bit when you are really talking about ultra pure water. Ultra pure water is about 18.2 mohms or about 0.05 micro-siemens. Most Reefers are after such ultra pure water in our experience. Thus, if there were such a thing as "ZERO TDS", it might be more appropriately measured around 0.05 micro siemens. Unfortunately, most (not all) inexpensive TDS meters can resolve at best about 5 micro seimens. That is several decades less sensitivity than required to be stating so called "ZERO TDS".
While 5 micro siemens conductivity (at an affordable price and rugged instrument easily operated and maintained) is very reasonable for for break-through detection to signal cartridge replacement required, it is clearly not sufficient to measure or crow about having "ZERO TDS" . Thus, postings where one has "measured" a system or component performance and state they have "ZERO TDS" should be careful to quantify the accuracy of the instrument they are using to make such a claim. Hopefully this will shed some light on... zero is not always zero."</span>
Barring any airborne chemical substances (ie:Raid) surrounding your water going in and out, all TDS related items are removed. Would I bottle and filter my water near 3 Mile Island? Probably not but the TDS would still probably read 0 after the fact.
If it's safe enough for you and I to drink, it ought to be safe enough for the reef after proper filtration. If you don't know where the water comes from, then maybe it should not be used..?? We know that chemicals are placed into the water to make it safe and the filter removes those chemicals to make it ultimately safe barring nothing airborne getting into it. Unless you want to put water through extreme lab testing and spend a fortune on it, we just have to go with the assumption it is good to go....
Jaycen,
Do you know how an RO membrane works? An RO Membrane is semi-permeable, meaning it has pore openings so small only simple, small molecules can go through it. Water is a simple, small molecule, much simpler that larger molecules like nitrate, phosphorus, and other dissolved solids that make up TDS. A typical 75 GPD RO membrane has an average rejection rate of 98%, meaning it only allows 2% of all TDS to go through it in addition to pure water.
Water pressure forces water molecules through the RO membrane. The 2% TDS that gets through then is passed with the pure water through the DI Resin, which gets any larger ions remaining.
There simply will not be (m)any larger ions in correctly made RODI water, primarily because of the RO Membrane itself. They cannot pass through the RO Membrane openings. It is not a matter of assumption, it is the way it is made and how it works.
If you want to know how a TDS meter works, look here:
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lmao
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CO2 is a gas that sometimes occurs in RO water that tends to generate a fair number of customer services calls we get. It doesn't register on the TDS meter but it uses up the DI resin capacity.
But to answer the original question - there is really no telling what remains in the water after it goes through a RODI system. If you are really interested you'd have to have your particular water analyzed in a lab. Be prepared to see a report with lots of "non-detects" in it. What we can say is that with a properly functioning RODI there is very very little other than H2O in the final product water.
Russ
But to answer the original question - there is really no telling what remains in the water after it goes through a RODI system. If you are really interested you'd have to have your particular water analyzed in a lab. Be prepared to see a report with lots of "non-detects" in it. What we can say is that with a properly functioning RODI there is very very little other than H2O in the final product water.
Russ
