dandy7200 January 22, 2008 Share January 22, 2008 When the color changes, it's a goner. Don't try and stretch it out just because you still read 0 TDS. TDS meters don't read Phosphates..... Link to comment Share on other sites More sharing options...
mogurnda January 22, 2008 Share January 22, 2008 Why not? Phosphate is highly charged, so it should show up as conductivity. Is it an ionic mobility issue, or is the critical concentration too low to be detected? Link to comment Share on other sites More sharing options...
dandy7200 January 22, 2008 Author Share January 22, 2008 Why not? Phosphate is highly charged, so it should show up as conductivity. Is it an ionic mobility issue, or is the critical concentration too low to be detected? Dunno. I read 0TDS with two differant TDS meters and 0.12 P04 with a Hanna colormeter. Changed the DI and now get a .000 reading on all three. Link to comment Share on other sites More sharing options...
YBeNormal January 22, 2008 Share January 22, 2008 Now if I could just remember where I read that article... Oh well. Here's a layman's summary of what I remember: DI resin will absorb and bond to charged ions until it nears saturation. Once it reaches saturation, the resin will continue to attract charged ions but becomes more selective, capturing particles with a stronger charge/bond and releasing particles with a weaker bond. Link to comment Share on other sites More sharing options...
magnetic1 January 22, 2008 Share January 22, 2008 My year old DI cartridge never changed color, but I started getting nitrates in my "RODI water". Perhaps the DI cartridge was still good and RO was not, but I went ahead and replaced them all for good measure. Man, when I was new to the hobby, I bought a $110 100GPH Coralife RO membrane. For those who are new to the hobby and are reading this... you can buy exact same ones for $40! Just not in a Coralife/Kent/etc box! Link to comment Share on other sites More sharing options...
YBeNormal January 22, 2008 Share January 22, 2008 Here ya' go, an arte from our old friend Randy H. Farley: http://reefkeeping.com/issues/2005-05/rhf/index.php Excerpt follows: Several issues arise relating to the depletion of the DI resins that aquarists need to be aware of. Primary among these is that when a DI resin becomes depleted, that does not simply mean that the water passes through just as it came from the RO effluent. It may actually be much worse from an aquarist Link to comment Share on other sites More sharing options...
dandy7200 January 23, 2008 Author Share January 23, 2008 Thanks for the article Bob, I figure I pay extra for the resin that changes color, I might as well use the color as the indicator of when to change it . If I am too busy, next time I will just bypass the DI until I can change media to prevent the leaching back. I guess I'll be doubling up on my GFO for the next month or so to mop up the damage. Link to comment Share on other sites More sharing options...
YBeNormal January 23, 2008 Share January 23, 2008 Bypassing the media may be even worse though since you could be allowing ammonia and other much more harmful stuff to pass. DI resin changes color gradually so it would be better to recognize that it's nearing the end and replace it before it is exhausted. It might cost you a few bucks a year extra but it's worth it. Better yet, add a second DI chamber in-line to mop up anything that leeches past the first one. When the first one is exhausted, rotate the second one into the primary position and put fresh resin in the second chamber. Link to comment Share on other sites More sharing options...
wreck January 23, 2008 Share January 23, 2008 I think it's time for to change my DI. Should I get a refillable DI cartridge or stick to one time use cartridges? I saw the RO/DI supplies on bulkreefsupplies.com. Is that good stuff? Thanks, Rick "Wreck" Link to comment Share on other sites More sharing options...
dandy7200 January 23, 2008 Author Share January 23, 2008 Bypassing the media may be even worse though since you could be allowing ammonia and other much more harmful stuff to pass. DI resin changes color gradually so it would be better to recognize that it's nearing the end and replace it before it is exhausted. It might cost you a few bucks a year extra but it's worth it. Better yet, add a second DI chamber in-line to mop up anything that leeches past the first one. When the first one is exhausted, rotate the second one into the primary position and put fresh resin in the second chamber. I have 2 DI's, they were both spent Maybe I need a whole array I think it's time for to change my DI. Should I get a refillable DI cartridge or stick to one time use cartridges? I saw the RO/DI supplies on bulkreefsupplies.com. Is that good stuff? Thanks, Rick "Wreck" I prefer to roll my own. I get the bulk from airwaterice.com Link to comment Share on other sites More sharing options...
YBeNormal January 23, 2008 Share January 23, 2008 Didn't the first cartridge exhaust before the second one began changing colors? Or are you saying you waited until the bitter end? If so, that defeats the purpose of having a second DI chamber! If I'm not mistaken, AWI's pre-filled DI cartridges are the refillable kind, aren't they? Link to comment Share on other sites More sharing options...
dandy7200 January 23, 2008 Author Share January 23, 2008 Didn't the first cartridge exhaust before the second one began changing colors? Or are you saying you waited until the bitter end? If so, that defeats the purpose of having a second DI chamber! If I'm not mistaken, AWI's pre-filled DI cartridges are the refillable kind, aren't they? yup and yup. cut me a little slack, I been busy lately :P Link to comment Share on other sites More sharing options...
davelin315 January 23, 2008 Share January 23, 2008 yup and yup. cut me a little slack, I been busy lately :P Oh, c'mon! You've only got one kid and two businesses, that's not an excuse. Get a couple more and then you can say you're busy! Whoops, forgot, it's first kid syndrome! Link to comment Share on other sites More sharing options...
dandy7200 January 23, 2008 Author Share January 23, 2008 Oh, c'mon! You've only got one kid and two businesses, that's not an excuse. Get a couple more and then you can say you're busy! Whoops, forgot, it's first kid syndrome! It's the 30 kids I have as employees that keep me running The one at home is a whole lot easier. Link to comment Share on other sites More sharing options...
YBeNormal January 23, 2008 Share January 23, 2008 Uh oh, I think I see what's coming next--the GSA 2lb standard 6 DI resin chamber! Great for folks with large tanks and busy schedules. Optional standard 8, 5lb and GSA Multiple Redundant Array DI (GSA MRADI©) chambers available upon request! Link to comment Share on other sites More sharing options...
jamesbuf January 23, 2008 Share January 23, 2008 cut me a little slack, I been busy lately :P Making room for that router huh? My back hurts already . At least that thing won't have to be lifted up onto a 4' stand though. Man, the things I do for free pizza Link to comment Share on other sites More sharing options...
Brian Ward January 24, 2008 Share January 24, 2008 Thanks for the reminder! Mine was definitely spent but I hadn't changed it since my TDS was still good. . . maybe this is why I have cyano on everything .... Link to comment Share on other sites More sharing options...
jnguyen4007 January 24, 2008 Share January 24, 2008 Can I wait till the DI cartridge nearly change color completely or do I need to replace it as soon as it starts changing color? Link to comment Share on other sites More sharing options...
Brian Ward January 24, 2008 Share January 24, 2008 Can I wait till the DI cartridge nearly change color completely or do I need to replace it as soon as it starts changing color? Wait till it's almost done changing color. Link to comment Share on other sites More sharing options...
jnguyen4007 January 24, 2008 Share January 24, 2008 Wait till it's almost done changing color. Thanks. Link to comment Share on other sites More sharing options...
YBeNormal January 24, 2008 Share January 24, 2008 Wait till it's almost done changing color. ...unless you begin to see a rise in the post-DI TDS that cannot be explained by a major TDS increase in your source water. Link to comment Share on other sites More sharing options...
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