TDS of RO/DI Unit

[bqq100]

What is the TDS after the RO membrane when you first turn on the water?  For my RO, it starts at about 130, but drops to <10 within the first 60 seconds, and <2 within 2 or 3 minutes.  Is this normal?  I usually flush the RO membrane for the first minute or so while the TDS drops to < 10, and flush again at the end for about a minute.  This has been happening even after replacing sediment/carbon filters and replacing the membrane. 

 

TDS post-DI is 0, so I'm not too worried about it, but it would be nice if I could fix the issue and save my resin a little bit.

[Origami]

Perfectly normal to have a high TDS burst at the start. If you can delay production of RO/DI until you need a good sized batch of it, you can extend the life of your resin. For example, my RO/DI system refills my primary reservoir three times a week.

[John Ford]

I have a valve before my di I open up before I fill my reservoir or mixing station and let it run until I'm close to my 001 then close it off. I usually start out at 080 and within 30 seconds or so it's stable at 005 or less.

[bqq100]

Thanks guys, good to know i'm not the only one! 

 

I already make my water in large batches (at least as large as I can) on a weekly or bi-weekly basis.  I also thought about adding a tee and valve before the DI, but I really don't want more valves and tubes coming off of the RO/DI unit 

[John Ford]

Mine is in my workshop so it makes it real easy for me to refill my glass of ice water as I'm drinking it. I understand keeping the least amount of failure points as possible though!

 

Thanks guys, good to know i'm not the only one!

 

I already make my water in large batches (at least as large as I can) on a weekly or bi-weekly basis. I also thought about adding a tee and valve before the DI, but I really don't want more valves and tubes coming off of the RO/DI unit