RO/DI

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bnr911

Aquarium Advice Apprentice
Joined
Jul 26, 2014
Messages
38
Location
Putnam, IL
Ok so I have been trying to get an answer to this question and keep getting mixed results. In my area all we have is well water and my LFS store tested it and said it would be fine to use with saltwater, but I really don't want to go that route. They sell water in their store for $1.00 a gallon ( holy crap). I do have access to RO/DI water at my work and I spoke to them and they will charge me $.01 a gallon.

They problem is every LFS I talk to said that the water would not be a good choice because it goes through a water softener first.

It goes through a softener, then the RO/DI unit, the filtered through a UV sterilizer.

Would this water be bad for my tank? I know they do regular maintenance on it and change filters often. I work at a printing company and we need to use RO/DI water for our presses so high quality water is a must. and the price is amazing.
 
water softeners add salt dont they? I know my old household softener required salt to work. But other than that, I am not too sure. You dont want any additives in your saltwater tank, just not sure if there is anything other than salt added to soften it.
 
water softeners add salt dont they? I know my old household softener required salt to work. But other than that, I am not too sure. You dont want any additives in your saltwater tank, just not sure if there is anything other than salt added to soften it.


See I 'm not sure either that is why I am questioning it. Would the Ro unit eliminate all of that making pure water? I just want to be safe. I was told that if I hooked up a RO/DI unit at my house I would be going through filter and membranes a lot since I have well water. I really don't want to pay $1.00/gallon, but idk what else to do.
 
Ok so I have been trying to get an answer to this question and keep getting mixed results. In my area all we have is well water and my LFS store tested it and said it would be fine to use with saltwater, but I really don't want to go that route. They sell water in their store for $1.00 a gallon ( holy crap). I do have access to RO/DI water at my work and I spoke to them and they will charge me $.01 a gallon.

They problem is every LFS I talk to said that the water would not be a good choice because it goes through a water softener first.

It goes through a softener, then the RO/DI unit, the filtered through a UV sterilizer.

Would this water be bad for my tank? I know they do regular maintenance on it and change filters often. I work at a printing company and we need to use RO/DI water for our presses so high quality water is a must. and the price is amazing.


From what I understand the softeners replace calcium and magnesium ions with sodium ions at a rate of about 3 sodium ions to one of the others. I imagine that the softener would be the first in line to protect the buildings pluming and appliances from limescale build up. Then once the softened after is in the internal system the RODI would strip it if practically everything depending on the rejection rate of the RODI unit.

Not owning saltwater fish or knowing much about salt water set ups I wouldn't know if it was preferable to have mineral-less water. Judging by what Carey has said I would imagine that that is indeed the aim? I'd say that that water would be ok to use mixed with salt.

You could buy a TDS meter to measure the dissolved solids in your companies water to make sure it is void of minerals. They are cheap enough on amazon.


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Yep, you want 100% pure water with nothing else in it as the salt mix has everything you need in it. So best to start with nothing and add exactly what you know you are adding than guessing.
The tds meter is a great idea too, that would let you know exactly what the water at work is at and if it is a single digit number it should do fine.
 
My RODI is hooked up after my water softener. I remember reading that using soft water will prolong the membrane's life. I have dual tds checker and always get 0 tds.
 
My RODI is hooked up after my water softener. I remember reading that using soft water will prolong the membrane's life. I have dual tds checker and always get 0 tds.


Yeh that makes sense.


Sent from my iPhone using Aquarium Advice
 
If the RODI unit is working properly it shouldn't matter if there is a softener in front of it. You should end up with something pretty close to just water.

I also agree with Pschmitt that it is better for the RO/DI unit membranes life but I am not sure how much that matters in this particular case.
 
So I tested the water at work and it has a 1TDS reading. So after reading through all the posts I think I am going to give it a try.

Thanks to everyone that posted. It really helped out. :)
 
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