My tap water has extremely high tds, Its at 507 ppm. My membrane seems to be working properly I get about 23ppm on the out bound side. So i figure I am getting a 95% rejection rate. Now this is the first MONTH of my new ro/di system, and I think my DI resin is exhausted. Before, my di resin was able to knock down the 23 ppm water to 2 ppm. Now 30 days after install I am getting 23 on the outbound side of the DI. After inspecting the resin it seems only 25% has changed color. I have a 150 gallon tank and have used about 70-90 gallons of RO/DI water. At this rate the DI resin is going to be my largest expense for my aquarium. Do I have any other options?
I need water purification options.
- Thread starter Globel
- Start date
Is your DI resin filled to the top??? I mean no area for water to get past it. Fill it up more if thats the case. Do you have two DI resin cartridges? If not, I would seriously consider adding a 2nd one. I run two DI resin cartridges and do 30 gallon water changes per week and also top off around 20 gallons water per week on my 210 w/ 100g sump and the resin lasts for around 2~3 months before being exhausted. I change out my membrane once per year.
-Steve
-Steve
LittleBeard
New member
Wow, that's a high TDS. Is it your own well or something? The EPA limits TDS at 500ppm, which your water would be over.
tkeracer619
New member
I would...
Increase pressure to membrane.
Reduce the ratio to maybe 6:1
Run dual non mixed bed resins and recharge them.
This should reduce the tds after RO and save some cash by regenerating the media.
Your membrane only has a 96% rejection rate. I would consider replacing it with a spectrapure that has been tested at 98%. My current membranes are running about 99%. If you hit 98% your di will last twice as long. 99% it should last roughly 4x as long.
The reason your color changing resin hasn't changed colors is because it is a general timer and not related the the actual tds removal capacity. My resin changes well in advance of needing it swapped out. My tds after membrane is 0-1.
Increase pressure to membrane.
Reduce the ratio to maybe 6:1
Run dual non mixed bed resins and recharge them.
This should reduce the tds after RO and save some cash by regenerating the media.
Your membrane only has a 96% rejection rate. I would consider replacing it with a spectrapure that has been tested at 98%. My current membranes are running about 99%. If you hit 98% your di will last twice as long. 99% it should last roughly 4x as long.
The reason your color changing resin hasn't changed colors is because it is a general timer and not related the the actual tds removal capacity. My resin changes well in advance of needing it swapped out. My tds after membrane is 0-1.
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