RO(DI) experiences with Ottawa City water

[fischkopp]

I am thinking about getting a RO(DI) unit for water purification and was looking out for experiences you have with such a unit. I am unsure of what to get at this point, but unit should be able to produce water with 0ppm (or very close to that), and it should produce a fair amount of water in a short time, lets say about 20gal in 2-3 hours. Not sure if that is reasonable. I like to move to storage once I have enough water as I have no space for a permanent installation.

So, my questions to you are:
What system are you using with Ottawa city water?
How low is the TDS [ppm] of your RO water?
And how many gallon does it produce per hour?

Also, do you think that DI is necessary to get very low TDS with our water?

Thanks for you input!

[bt]

You can ALMOST get to 20gal in 3 hours with a 150GPD unit.  Any RO/DI unit worth buying will give you 0 TDS out.

I use the BulkReefSupply 5 stage Chloramine Plus system.  I get 0 TDS out.  I get about 3gal/hour.  TDS between the RO and the DI is in the low-mid 30s.

[Hookup]

I'm not sure of my brand name. But I wanted to ad that water pressure and temp have a lot to do with the effective TDS and the production rate. Or so I'm told.   I run about 25feet of tubing into my sump to warm the water a bit before hitting the Ro/di.

[bt]

IIRC it's "the colder the better" for RO efficiency.

[leemay]

i was going to say that too!

IIRC it's "the colder the better" for RO efficiency.

[Hookup]

Geesh!  I hope others chime in and settle the cold/warm issue. I might be doing it all wrong. 

Wouldn't be the first time. Or likely last lol

[leemay]

I am thinking about getting a RO(DI) unit for water purification and was looking out for experiences you have with such a unit. I am unsure of what to get at this point, but unit should be able to produce water with 0ppm (or very close to that), and it should produce a fair amount of water in a short time, lets say about 20gal in 2-3 hours. Not sure if that is reasonable. I like to move to storage once I have enough water as I have no space for a permanent installation.
So, my questions to you are:
What system are you using with Ottawa city water?
How low is the TDS [ppm] of your RO water?
And how many gallon does it produce per hour?
Also, do you think that DI is necessary to get very low TDS with our water?
Thanks for you input!

aqua vision 75, got it from Ray
ro= 8 tds
di= o tds
75 gal per day it is rated for
yes di is necessary to get 0 tds, may depend on incoming tds though

[bt]

I'll see if I can dig up the source of colder=faster.

[leemay]

Geesh!  I hope others chime in and settle the cold/warm issue. I might be doing it all wrong. 

Wouldn't be the first time. Or likely last lol

i think the benefit of warmer water is that the pressure is higher wich  
is good, but colder water holds less :impurities"

i could also have the wrong info haha

[Hookup]

While we're digging up research info. Here is a related question


How come tap water doesn't have copper in houses that are all copper plumbing?  I'd think trace amounts would build up over months if not years then.

[leemay]

While we're digging up research info. Here is a related question


How come tap water doesn't have copper in houses that are all copper plumbing?  I'd think trace amounts would build up over months if not years then.

i think your right if the water sat in the pipe for months/years, but it is usually flowing through the pipe.

[Rybren]

IIRC it's "the colder the better" for RO efficiency.

I believe that it's actually the opposite.  Warmer water is more effecient.  I'm not sure why and can't find the link anymore that explains it.  With my 75GPD unit, there is a significant drop in production in the winter.

For Fischkopp,  you'd want to look at a "Chloramine" unit, or at the very least, a unit that has 2 carbon stages.  As you likely already know, Ottawa uses chloramines rather than chorine.  Chloramine is a mixture of ammonia and chlorine.  If it all doesn't get stripped away before the RO membrane, the chlorine will have a tendency to greatly reduce the life of the membrane.

[Greatwhite]

I remember when setting up my Aquasafe RO/DI that the instructions clearly indicated NOT to run warm water through it because it degrades the membrane faster.  I don't think there was any more information on it than that, really.  Mine is just hooked into the cold water line at a wash basin, and into a 30G tank with a heater and powerhead. 

When I have time, I plan on running a line directly to my sump compartment where a 5G bucket lives, and throw a heater in there - and my Tunze 3155 space Osmolator takes care of my top up.

Oh, and as for the RO/DI unit, Aquasafe works well - but you'll want to swap the 5 micron carbon filter with 1 micron to remove chloromine.  I get 100GPD out of it, at 0 tds...

[bt]

For Fischkopp,  you'd want to look at a "Chloramine" unit, or at the very least, a unit that has 2 carbon stages.

It's not enough to have 2 carbon stages, it's also the size rating of the carbon stages.  IIRC, you need the second carbon stage to be rated for 1 micron to properly deal with Chloramine.

[ray]

In my understanding that to be truely effective in removing CHLORAMINES from thr the water it is the type of carbon and the most popular used method is a sediment filter,activativated carbon filter then CATALYTIC carbon(which is the one for chloramines)
RO membrane then your DI

Ray

[Rybren]

+1 to Ray.  I do not belive that the pore size is relevant to CHrolamine removal (but I could be wrong)

[Rybren]

Here's a link to an article by Randy Holmes-Farley on Chloramine.

http://reefkeeping.com/issues/2003-11/rhf/feature/

For those who don't want to read the entire thing, here's the down and dirty...

Lessons Learned and Suggestions:

1. Most RO/DI systems seem capable of removing chloramine adequately for aquarists.
2. The carbon cartridge may become less useful over time, and it is possible that the chloramine removal effectiveness of a system may be lost before the DI appears to need changing.
3. Cheap sediment cartridges may expose the carbon cartridge to unnecessary fouling, which may permit chloramine to pass through the system. Cartridges should be replaced as soon as the pressure drops significantly, even if RO/DI water is still being produced at a reasonable rate or purity as measured by total dissolved solids.
4. Testing for chlorine and chloramine is easy, so any concern is easily reconciled. 

[fischkopp]

Thanks everyone for their input!

It looks like getting the TDS down to 0ppm isn't a a problem if the RO unit has DI. That's good!

I read a bit up about the cold/hot water issue. With increasing temperature, the holes in the membrane will expand, allowing more water to pass through. But the bigger holes also allow more impurities to pass. Hot water is said to damage the membrane. For best RO water it's recommended to use cold water.

I didn't think about chloramine. Do you trust your RO/DI to remove it or do you still add a bit of prime to be on the safe side?

[bt]

I trust mine, but I also made sure to get one with the right carbon stages to handle it.

[Rybren]

I also trust my unit to remove all of the chloramine.