DI Tank Issues


I have a Frankenstein pure water system that I’ve been building over the years. The current version is on a Wash-it Pro cart. It was a legacy white 10" Carbon filter housing. 40" stainless steel membrane housing with the standard Xero membrane. (Currently priced $340) and the older model 30" PVC Pipe with DI cartridge filled with virgin resin from Xero. The system sits horizontal in my truck at all times. The water in my area is very high TDS, around 400 on average.

My issue is I’m can’t seem to get my tds down to 0. On good days I hover around 20 and I get spots on hydrophobic windows unless I do a water only squeegee.

I know my RO membrane is starting to fail because its only bringing TDS down to 23% after less than a year. (That was probably my bad for not switching out my Carbon filter more regularly) But I’m debating on switching out my PVC DI tank for a 21" DI tank that is on the newer model Xero Pure sustems. (The one that feeds water from the cap) I notice that no matter how well I pack the resin currently, it always has a large gap after water runs through it. I assume I have channelling issues especially since it sits horizontal. I’m hoping the other 21" style DI tanks don’t have that issue. But even yesterday I changed out the resin on the job and I didnt get 0 TDS. It only brought the RO water from 44 to 18. So I’m a bit frustrated.

I also hope that I can keep the system horizontal since that works better in my small truck.

As far as I know keeping it horizontal is not a problem. Mine too is always horizontal. One problem that does show up is not packing the DI resin tight enough. Even when it seems tight I sometimes have to repack because it settles in. When the TDS becomes erratic and wont go below 20 or so and sometimes goes much higher, that is usually what is going on.

I no nothing about the cartridge type systems, if you do get a standard tank that will need to sit vertical to function.
What is your incoming TDS. I would be replacing the membrane of your RO tbh.

Thank you, that’s good to know you can lay it flat with no issues. I’ll try packing it in tighter as well

Thank you, I’ve got the Axeon membrane on order, hope it helps

Cold weather will dramatically reduce the efficacy of the RO membrane. Our TDS out of the RO more than doubles this time of year. Keeping it warm when not in use helps.

Yes. Keep it warm.
I started putting my heat lamp in the pickup at night last week.