Rodi maintenance

[CStrickland]

Hi all,
When I finally switched to rodi I was committed to taking good care of the parts so they last a long time. Everything I read says the sediment filter gets like 6 months or until you see a pressure drop, I think. Mines only 3 months and the pressure is the same as day one. But it looks grooooosss! It's really dark brown!
Is that ok? Do I just have especially grody looking sediment?

 

[Marchillo]

That is interesting. I've been using mine for a year and haven't changed anything. I have great pressure and my filters look white. I get zero tds coming out.

I'm sure it's the tds of the water going in? Mine is consistently around 27 tds going in.

I always think I should change it but if I'm getting zero why would I?

I think if you are getting zero it's all good.

 

[CStrickland]

Yeah. I get zero. Think the first can takes out big chunks that might not raise the tds, but they would clog up the other, finer, filters so they can't catch tds as good. I meant to say also that my waste ratio is 4:1
My tap tds was a little more than 100 when I last checked (last month maybe?) it's never been scary high

 

[Mrs. Music]

I would change it if it was visibly soiled at 6-8 months even if my pressure was unchanged as a preemptive measure. What size micron is it? just curious. I recently figured out that I screwed up when I changed my gallons per day ro membrane.

 

[gone fishin]

I think mileage will differ from place to place. By the time my well water gets to my RO/DI it has already passed through a sediment filter coming into the house and a water softener. I have found that I change mine yearly usually in the fall. The house filter gets changed semi annually.

Maybe change them out and mark it on the calendar to track.

 

[CStrickland]

I would change it if it was visibly soiled at 6-8 months even if my pressure was unchanged as a preemptive measure. What size micron is it? just curious. I recently figured out that I screwed up when I changed my gallons per day ro membrane.

It's 1 micron, 3 months old. It's a 90 gpd unit with the original membrane.
IDK how many gallons I've made, but I do weekly 5g changes plus weekly 5g topoff so I would guess less than 150 g
I feel like it started to look dingy almost right away. At first I was like "yay, it's making the water so clean!" Now I'm like "dude, really?"

This is Boston city water, which has a decent reputation. My building is pretty old so idk maybe the pipes are grody?

 

[jason2459]

Yep, I would change it out if it looks "soiled" or pressure drops. Around 8-10 months with my current water supply. Used to be sooner 4-6 months on my old water supply. I use a decent amount of water each month.

I switch out my carbon blocks every 6 months in months divisible by 6 which makes it easier for me to remember which would be June and December.

I switch out my dual membranes on years divisible by 3 so I don't have to remember the last time I swapped them out. I did this in 2009, 2012, 2015, and will again in 2018. I also make sure to back flush the membranes after each use. There are automatic flushing kits but I never got around to getting one.

DI I swap through 3 stages of it. I get color changing but used to not change it out until I saw 1 on my TDS meter which was often after all the color has changed. Now as soon as I see 99% of the color changed I take that last stage with the newest DI resin (3rd stage) and put it into the stage before it (2nd stage). Take that 2nd stage's DI cartridge and put it into the stage before that which is the 1st stage. Then discard the oldest DI resin that was in the 1st stage that was replaced by the DI cartridge from the 2nd stage. I hope I explained that clear enough. This has saved me some DI resin quite a bit. Even if its registering 1 it's still reducing the TDS to at least that point and has some life left.

So now I'm usually seeing a drop from 250ish going into my membranes to 9ish out. Then after my first DI stage 2ish, after my 2nd DI stage 1ish, and after the last DI stage 0.

 

[CStrickland]

hmm, if I switch it as soon as it's not white that'll be less than a month of use. Plus I'm about to upgrade from the 55 to a 120 w/ 30g sump. I see spectrapure sells a zetazorb can you can backflush. Looks like a 5 micron rinsable pre-filter sorta. Maybe that with a .5 micron in the first can of my unit would work...

 

[Mrs. Music]

I would not worry about it earlier than 6 months unless the pressure dropped off.

 

[Baccara]

I usually change my sediment filter every 6 months and the others yearly. A pre and post DI tds meter is what I use as an indicator. My sediment filter starts to yellows around 3-4 months and I wait until my pre DI is around 25 ppm.
I agree it defiantly depends on where you live and your source water. As long as your making 0 TDS it should be good.

 

[jason2459]

hmm, if I switch it as soon as it's not white that'll be less than a month of use. Plus I'm about to upgrade from the 55 to a 120 w/ 30g sump. I see spectrapure sells a zetazorb can you can backflush. Looks like a 5 micron rinsable pre-filter sorta. Maybe that with a .5 micron in the first can of my unit would work...

Soiled like what you are seeing now. Not just discolored. You could use a chlorine test to know when to change out the carbon. I just do it every 6 months to avoid testing and be safe. They are cheap.

 

[Mark9]

Post your question in the Spectrapure forum. You'll get your answer quick.