Did I break my RO/DI unit?

reefrookie2013

New member
I am new to reef keeping this year, making lots of rookie mistakes along the way. Today I did the following:

I have a 6 canister RODI system with
1 micron sediment filter
5 micron carbon block
0.6 micron carbon block
RO membrane
DI resin
DI resin

Unfortunately I hooked up the tap water to the output area today :-( Was tired and not being careful. It must have run for 1 minute or two when I finally realized what I did. Then, I hooked it up the correct way, and turned on the TDS, which measured 160 in and 003 out while it was being primed the correct way, then when I flipped the valve on (inline), it measured 023 and then after about 30 minutes it measured 003. None of this went to the reservoir.

So, do you think I am safe to use the output of this RODI system or will I have to replace everything in the system before I make RODI water safely again?
 

camblonie

New member
You're concerned because TDS is 3? Keep running it and it will probably clear. 3 shouldn't really be bad anyway.
 

reefrookie2013

New member
Thanks

Thanks

Thanks so much for your thoughtful replies.

My more immediate worry upon posting was whether there would be something harmful that might have gone into the system on the output side that wouldn't have come out with a good flushing.

Also, I wanted to know what would define a good flushing. Can I be comfortable that TDS out:in would be an adequate dipstick of the system having been flushed out of contaminants enough?

I will keep running the system, maybe for another hour, to see if I can get the TDS out to be less, and I'll let you know?
 
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scottwhitson

New member
Is the 3 TDS before or after the DI containers? If it is after your DI then your DI resin is used up and needs replaced. Also what is your TDS of your water that you are feeding into the RO/DI? Good membranes have a 98% or better rejection rate.
 

awolusa

New member
Is the 3 TDS before or after the DI containers? If it is after your DI then your DI resin is used up and needs replaced. Also what is your TDS of your water that you are feeding into the RO/DI? Good membranes have a 98% or better rejection rate.

All you did is back flush it. You are supposed to do this every once in awhile anyway. There was not enough time to add something bad. You most likely did not put more than a Trimble full of discharge into the system.
 

fishgate

Active member
RO/DI is a relatively new phenomenon in the SW world. People got along just fine for many many years before it. No need to flip out over something so very minor.
 

Art13

New member
I did the same thing with mine and i called the company that makes it, they said if it was only for a short period of time maybe an hour or two i would have been fine but me in all my brilliance didn't look at the arrow on the canister pointing the other way and left it that way for a week, i just thought i was getting amazing GPH. I had to replace the membrane on the unit but other than that it is fine.
 

Spyderturbo007

New member
You're concerned because TDS is 3? Keep running it and it will probably clear. 3 shouldn't really be bad anyway.

I'm of the school that anything over 0 TDS needs to be addressed unless you know what is causing the non-zero TDS reading. For example, if it's Sodium getting through the system it isn't an issue, but if it's Copper, you have problems.
 

thegrun

Team RC
While I also live in the .000 TDS world, I suspect if you run the filter a little longer all the impurities will be flushed out of the system and your TDS will drop back to zero.
 

reefrookie2013

New member
Thanks to all for your advice and anecdotes!

The update is that 1) I finally figured out that the TDS on the unit was for the RO membrane out:in, so that is 160:3, and 2) I tested the TDS on the actual output water and it was 000.

Unfortunately, I tested phosphate on the same water after 2 hrs of flushing and it was 0.08, so I'll have to change the DI resin anyway. :-\ Don't want to add to my phosphate worries since I finally got it down to 0.03

Thanks, again!
 
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