RO/DI question

BrotherNature · 02/01/2018, 08:35 PM

I've got a 4 stage RO/DI unit I got from BRS. How do I know when I need to replace the filters? Is a TDS reading of 1 an indicator or can I let this ride for awhile? Can I continue using it at 5, 10, 15, or 20? How do I know what's toxic? Thanks.

slief · 02/01/2018, 08:37 PM

My RODI has 2 DI stages. As soon as my first DI stage reads anything above 0, it gets swapped. Same with my 2nd DI stage. Anything above 0 on the the DI is not good and means the DI cartridge should be replaced immediately. It’s not just the TDS but more importantly, what that TDS consists of. Regardless, if your TDS meter is reading above 0, it’s time to replace your DI cartridge.

Opus123 · 02/02/2018, 10:35 AM

Depends on how technical you want to get about the process. Some people measure the pressure after the filters and replace once it starts dropping because that means the filters are becoming clogged. If you don't want to do it that way, and many don't, then the rule of thumb is to change the sediment and carbon filters every 6 months. The RO membrane when it drops below its stated efficiency level, which is usually 95% or higher. The DI should be changed once you start getting a TDS above 0.

outy · 02/02/2018, 11:39 AM

Quote:

Originally Posted by BrotherNature

How do I know what's toxic? Thanks.

I measure water leaving membrane before DI, you should know that number.

I change membrane when I get an increase in TDS numbers of just 2tds after being flushed and running for a minute or two.

I change pre filters and carbon blocks when they change colors, as I have a lot of iron in my water. I never let the 3rd carbon filter change color, only the first two before I change all media.

02/01/2018, 08:35 PM	#1
BrotherNature Registered Member Join Date: Jan 2017 Location: California Posts: 39	RO/DI question I've got a 4 stage RO/DI unit I got from BRS. How do I know when I need to replace the filters? Is a TDS reading of 1 an indicator or can I let this ride for awhile? Can I continue using it at 5, 10, 15, or 20? How do I know what's toxic? Thanks.

02/01/2018, 08:37 PM	#2
slief RC Sponsor Join Date: Sep 2009 Posts: 14,173	My RODI has 2 DI stages. As soon as my first DI stage reads anything above 0, it gets swapped. Same with my 2nd DI stage. Anything above 0 on the the DI is not good and means the DI cartridge should be replaced immediately. It’s not just the TDS but more importantly, what that TDS consists of. Regardless, if your TDS meter is reading above 0, it’s time to replace your DI cartridge. __________________ Director Customer Support Royal Exclusiv USA For All Royal Exclusiv & Bubble King questions please refer to our Sponsor forum: http://www.reefcentral.com/forums/fo...play.php?f=745 Current Tank Info: 480G display mixed reef, 90G sump, 90G refugium, 60G display refugium. Check out my build thread: http://www.reefcentral.com/forums/showthread.php?t=1783476

02/02/2018, 10:35 AM	#3
Opus123 Registered Member Join Date: Jul 2005 Location: North Texas Posts: 605	Depends on how technical you want to get about the process. Some people measure the pressure after the filters and replace once it starts dropping because that means the filters are becoming clogged. If you don't want to do it that way, and many don't, then the rule of thumb is to change the sediment and carbon filters every 6 months. The RO membrane when it drops below its stated efficiency level, which is usually 95% or higher. The DI should be changed once you start getting a TDS above 0.