When to change DI media

[briangg57]

I have an RO-DI unit and when the DI media is new, my TDS is 0 TDS. My RO water is 16 TDS. It's been a few months since a change and my TDS for my DI water is 3. How high do you guys let it get before changing the media. I know a lot of people just use RO water which is way higher than TDS 3. I'm going to change it soon but I'm just wondering how high you guys get before a change. Thanks, Brian

[spleify]

I change mine every 6 months. I go by the color changing of the media also to determine if I need to change sooner, or if I can go a little longer. I would look into changing the RO filters too. How long have you run the RO filters for. I personally get 0 from RO, and in turn 0 from DI

JME

HTH

Spleify

[akaimal]

I change mine every 6 months too..

[psyrob]

Dude, I think the DI should be 0 and it should be changed whenever it goes higher than that. I believe when it goes higher than 0 that means the DI is exhausted. Post this in the Filter Guys forum in the sponsers forum. They give great advice...

[Toddrtrex]

Anything above 0 and I would at least order new resin, and would change it as soon as you can. Personally I don't trust the color changing, and go by what my TDS meter tells me. Can't really go by time, since everyone's water is different.

[briangg57]

<a href=showthread.php?s=&postid=13666435#post13666435 target=_blank>Originally posted</a> by spleify
I change mine every 6 months. I go by the color changing of the media also to determine if I need to change sooner, or if I can go a little longer. I would look into changing the RO filters too. How long have you run the RO filters for. I personally get 0 from RO, and in turn 0 from DI

JME

HTH

Spleify
You must have a super duper RO unit to get 0 tds out of it. That's way above normal. What kind do you have and are you sure you tds meter is working correctly?

[Roy G. Biv]

I usually get 3-4 out for the RO and 0 out of the DI. I think its unusual to get 0 right out of the RO. I dont think any RO is %100 efficient.

For the original post. I think 16 is a little high as well. I guess it all depends on whats going in though. Blasting the DI with 16ppm will exhaust it pretty quickly.

[crvz]

When my DI gets above 3-4 I usually replace it. An RO membrane will reject 90-96% of TDS from the source, so I'll measure water out of the membrane to know how well it's performing for replacement.

[spleify]

Yes my RO is 0. The TDS going in is only 86.

I have two different TDS meters, one dual in line meter and a hand held unit. Both read 0 after RO and 0 after DI.

I have no reason to doubt my results. At one time I had 3 different TDS meters(before I sold one to a buddy) and they all would read 0.

JME

Spleify

[briangg57]

<a href=showthread.php?s=&postid=13672102#post13672102 target=_blank>Originally posted</a> by spleify
Yes my RO is 0. The TDS going in is only 86.

I have two different TDS meters, one dual in line meter and a hand held unit. Both read 0 after RO and 0 after DI.

I have no reason to doubt my results. At one time I had 3 different TDS meters(before I sold one to a buddy) and they all would read 0.

JME

Spleify
Wow, Your lucky, My water sucks and has 246 TDS going in and 16 after going through RO. Thanks for the replies and happy reefing. Brian

[Garage1217]

246 in is great *LOL* I am at 650-700 in. After my max cap kicks the crap out of the water, I am down to 0 TDS after the DI stages. If I see anything above 3 TDS, I chance out my DI cartridges. Spectrapure recommends changing them at 5 TDS.

[rwessels]

Once it gets above 0, it is already too late to change it. DI will trap all sorts of impurities but when it is exhausted, it will release many of the bad ones first. 1 TDS of certain things isn't that bad, but 1 TDS of other things could be. The best setup IMO is 2 DI's. Measure after the first one, when it reads above 1 TDS, move the 2nd one in its place and replace the 2nd one with a brand new one. That way you never release anything above 0.

If you cannot use 2 different units, then just check OFTEN and replace when it gets above zero. Anything over zero means either your meter is bad or the resin is exhausted.

[runningstix]

my ro is also at 0 as I live 5 blocks down from spleify.

we have clean water in colorado!

[spleify]

<a href=showthread.php?s=&postid=13674339#post13674339 target=_blank>Originally posted</a> by runningstix
my ro is also at 0 as I live 5 blocks down from spleify.

we have clean water in colorado!


Yes we do!!

[Rae C.]

Love that clean Colorado water! My RO is zero and incoming water is 46. I'm up the hill from runningstix and spleify.