TDS too high?
- Thread starter SAKTEK
- Start date
Reading on line I found this post.
"You should also have flushed the new filters to waste before putting them through the membrane the flushed the membrane to waste before putting it to the DI. Prefilters and carbon block need a rinse. Membranes need a bigger rinse and if you do not you pass a lot of unnecessary jumk to the DI resin wearing it out prematurely."
How true is that???
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"You should also have flushed the new filters to waste before putting them through the membrane the flushed the membrane to waste before putting it to the DI. Prefilters and carbon block need a rinse. Membranes need a bigger rinse and if you do not you pass a lot of unnecessary jumk to the DI resin wearing it out prematurely."
How true is that???
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Depending on what RO membrane you installed, you may be right on track. If you installed a high gpd membrane with say.. only a 90% rejection rate, a TDS of 16 post membrane isn't that unrealistic. Even a 75gpd filmtec, which advertises a high 98% rejection rate (but can be as low as 96%), would put you right at the numbers you're seeing. Figure about 400 TDS coming in (average for me) x 96% rejection rate (minimum acceptable rate for a 75gpd filmtec).. leaves you about 16 TDS post membrane. That high of TDS could wear out your DI quickly.. twice as fast as if your tds was only 8 post membrane. Maybe you just need some new DI resin? Did you change it out as well? Was it fresh? Was it from a reputable vendor?
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If you haven't made much water through the new filters, the DI shouldn't have exhausted that quickly.. Maybe it wasn't packed tightly enough? Maybe the RO membrane hasn't quite broken in yet.. the TDS may still go down, as you run more water through it.
Keep in mind, in my example scenario in the last post, I was figuring in a 400 TDS coming in.. I know sometimes when I check my incoming TDS after a day or two of rain, the incoming TDS is over 700! That would wear out your DI even quicker.. This is the reason it is very important to buy the RO membrane with the highest rejection rate you could possibly find.. It saves money in the long term on the costs of replacing DI resin..
The DI cartridge you installed, was it refillable? If so, you can always order $10 worth of new resin from BRS or any of the other vendors, and get your TDS back down to 0, if it doesn't go down on its own.
Keep in mind, in my example scenario in the last post, I was figuring in a 400 TDS coming in.. I know sometimes when I check my incoming TDS after a day or two of rain, the incoming TDS is over 700! That would wear out your DI even quicker.. This is the reason it is very important to buy the RO membrane with the highest rejection rate you could possibly find.. It saves money in the long term on the costs of replacing DI resin..
The DI cartridge you installed, was it refillable? If so, you can always order $10 worth of new resin from BRS or any of the other vendors, and get your TDS back down to 0, if it doesn't go down on its own.
