RODI Advice - Resin exhausting way too fast

[s&sreef]

So I run a water saver BRS 4 stage unit. Recently the resin is getting used up extremely fast, in like 2 weeks fast. I'm trying to figure out why and look for some solutions. I changed all filters less than a month ago, and the membranes back in march.

1. The pressure recently dropped (they are doing some water main construction nearby I don't know if this is the culprit but I went from 65psi to 60, okay 58. I changed the sediment filter to see if it was clogged this had no effect. Possible solution booster pump.

2. TDS creep, whenever you turn on your RODI residual TDS gets through before dropping, my in rating is typically 120 or so then drops to 8 after a minute or 2 -solution TDS creep bipass

3. I have an auto shut off kit, I let my system run all day today, when I came back the kit has stopped the water flow, my TDS on the in probe had risen to 172!! A tds bipass would not help with this build up.

4. Its just not enough for the water here, our tap water was 482 tds the last time I tested it, considering adding another carbon block before the membrane and dual DI cartidges after in hopes of extending resin life.

5. Maybe I seated the membranes wrong, I honestly don't think I did, I checked today they are in there pretty firm.

Any solutions suggestions, would be appreciated.

 

[JohnK]

When you let it run continiously with the auto shut off it's constantly cycling on and off, making "TDS creep" a constant issue. Install a shut off valve and use it to make controlled batches and you will see a major decrease in the issue you are having.

 

[s&sreef]

The clean water goes to a t connection to two buckets, each bucket has a shut off valve so the creep still occurs even after the shut off valves stop the flow, the unit itself also has a shut off valve so it does not waste water.

 

[dds]

I have the same issue, but I have a well & what exhausts my DI resin so quickly is CO2. Could your issue be the same?

 

[JohnK]

The clean water goes to a t connection to two buckets, each bucket has a shut off valve so the creep still occurs even after the shut off valves stop the flow, the unit itself also has a shut off valve so it does not waste water.

Even set up like that it will cycle on and off if nothing else then just from slight evaporation loss. There may be other factors, but this is a common issue. RO units work best making large batches, small batches (like 5 gal buckets) and relying on the auto shut off system to keep it shut off between batches is usually problematic. (it's very easy to rule this in or out, just try it and see if it makes a difference, adding a valve on the feed line costs about $3 and takes 30 seconds)

 

[Brady]

Test the co2. That’s most likely the culprit. If that’s the case throw a air stone in the bucket that you run water into and it will bubble out the majority of the co2 to almost 0.