Normal TDS & When To Change RO Filters

[JSkeleton]

i dought it. i put over 200 gal so far threw mine and just had to change one stage of di, i have 3.
and yes you can add on.

So you bought your DI separate? Not sure what to look for or get (in Canada)

 

[JSkeleton]

@KStatefan is correct there is no DI stage. You can add a DI stage RO buddy sells the DI separately or you can buy it from another company and add it to the system. Just add it from the output of the ro membrane (RO water) to the DI resin. If you do buy the RO Buddy di stage I will warn you that I have used an auto-shutoff and the pressure cracked the top it two times. Both times the DI canister was new. It didnt cause a serious leak only when the float valve would shut. From your result I would guess that your water pressure isnt as high as mine (Mine is 65 psi) because you are getting 4tds from the RO filter from 70 tds tap.

Ah gotcha! How often do these DIs need to be changed anyways?

 

[JSkeleton]

Definitely shouldn’t have burned through filters that quick. My TDS is about 50 with an output of 0. I’ve had my unit for a year without changing filters and I make maybe 200-250 gallons in a year

If your output is 50 and mine is close only at 70, then why on earth isn't the 3 stage sufficient for me?

 

[JSkeleton]

I've never used DI before. Typically my water after RO is around 10-15 ppm (starting from over 1000). I suppose it all depends on what that 4ppm is, but I just don't see the value.

So you've ran your tanks with your RO sitting at 10-15 with no issues? How do you know when to change the membrane/filters?

 

[JSkeleton]

Dont complicate.....

Ro membrane rejection rate is 94-98%, so its almost impossible to have 0 tds without di resin....

As for changing sediment/carbon filters, some say 3 months, some say 6, for me, once a year is good enough, no matter what condition is on prefilters, di will always (ok, almost always) get that to 0.....

Downside is quicker burning trough resin, aka more often u need to change it.

Either live with 4 tds, which is acceptable for some, or buy di cartridge and u will have 0 tds...

Ah gotcha! So a DI Resin has to be changed quite frequently then? And 4ppm is livable?

 

[Koh23]

Well, depends of definition "frequently"....

In my case, 2-3 times a year change is optimum, not to deplete resin completely, but to be safe, i change it....

300ml is my cartridgs, average 1000ml pack of resin is 30-ish $, not cheap, but, whole year of peace of mind is priceless

 

[MONTANTK]

If your output is 50 and mine is close only at 70, then why on earth isn't the 3 stage sufficient for me?

I’m assuming you’re either missing the DI stage or the membrane. I believe it’s the DI which is important for getting TDS down to 0

 

[JSkeleton]

Few more more questions:
1. What does it mean to "flush" the membrane?
2. How often does a membrane have to be replaced on average?
3. How often (roughly) does Carbon have to be replaced?
4. How often (roughly) does Sediment have to be replaced?

 

[JSkeleton]

I’m assuming you’re either missing the DI stage or the membrane. I believe it’s the DI which is important for getting TDS down to 0

Yeah I don't have a DI, but I'm hearing some people say 4ppm isn't so bad? I know 0 is ideal, but man to have to throw in a DI too now and replace those every few months, at this point I'm ready to bow out and go back to freshwater as it's getting more and more expensive to maintain.

 

[Mmonk005]

Here’s the DI for your unit. I have the same unit. Very easy to add on.

Aquatic Life DI Color Changing Mixed Bed Resin Cartridge https://a.co/d/0xPGVX5

 

[LeftyReefer]

Few more more questions:
1. What does it mean to "flush" the membrane?
2. How often does a membrane have to be replaced on average?
3. How often (roughly) does Carbon have to be replaced?
4. How often (roughly) does Sediment have to be replaced?

I had a typical 4 stage setup, and then I added a second sediment filter, which I then changed over to running double carbon blocks instead.

sediment
carbon
carbon
RO membrane
DI (single mixed bed)

My tap water in is 100 TDS and I typically get 1 or 2 TDS out of my RO membrane and the single mixed bed di stage removes that down to 0 TDS. My system has been running for over a year and I've only had to change my sediment and carbon blocks once. My RO membrane is still working fine and my DI stage still hasn't shown any color change and is still polishing my water to 0 TDS. I'm well over a year use on my DI cartridge and it hasn't even started turning color yet.

So I've gone through about $10 in filters in the first year. 1 sediment and 2 carbon blocks.

I make about 35 gallons of RODI per week. 10 gallons goes into my ATO reservoir per week and the other 25 gallons go to water changes between my DT and QT tanks. I have a 100gpd system.

 

[Hermie]

Yeah I don't have a DI, but I'm hearing some people say 4ppm isn't so bad? I know 0 is ideal, but man to have to throw in a DI too now and replace those every few months, at this point I'm ready to bow out and go back to freshwater as it's getting more and more expensive to maintain.

honestly dude 4ppm is not that much for DI resin to filter out. I hardly change mine but it's overdue right now. Like once per year or half a year. But honestly if you think 20 bucks for DI resin is too expensive for keeping CORALS including SPS then you are in the wrong hobby. IMO bite the bullet and add DI to your system. Unless it's a FOWLR system.

 

[JSkeleton]

Also, would this be a good pressure gauge to monitor when to be changing the sediment?

 

[JSkeleton]

honestly dude 4ppm is not that much for DI resin to filter out. I hardly change mine but it's overdue right now. Like once per year or half a year. But honestly if you think 20 bucks for DI resin is too expensive for keeping CORALS including SPS then you are in the wrong hobby. IMO bite the bullet and add DI to your system. Unless it's a FOWLR system.

It's not 20 bucks, it's 20 bucks for ANOTHER filter on top of the $40 for carbon + sediment on top of the salt, and it just seems to be adding up VERY QUICKLY to being a lot more than I had expected just to MAINTAIN the tank. Spending cash for an initial setup or for fish/coral initially is one thing.

That said, I hadn't even decided on whether to go down the Coral route or not, I just wanted Saltwater because the fish are way nicer than Fresh (and my Wife really wanted some Saltwater fish), but perhaps you're right, maybe Saltwater was the wrong hobby, who knows.

 

[dschuffert]

I change my sediment and carbon filters out annually. I change my DI resin when the color changes for all the resin in the container and my TDS output starts reading higher than zero.

 

[JSkeleton]

I had a typical 4 stage setup, and then I added a second sediment filter, which I then changed over to running double carbon blocks instead.

sediment
carbon
carbon
RO membrane
DI (single mixed bed)

My tap water in is 100 TDS and I typically get 1 or 2 TDS out of my RO membrane and the single mixed bed di stage removes that down to 0 TDS. My system has been running for over a year and I've only had to change my sediment and carbon blocks once. My RO membrane is still working fine and my DI stage still hasn't shown any color change and is still polishing my water to 0 TDS. I'm well over a year use on my DI cartridge and it hasn't even started turning color yet.

So I've gone through about $10 in filters in the first year. 1 sediment and 2 carbon blocks.

I make about 35 gallons of RODI per week. 10 gallons goes into my ATO reservoir per week and the other 25 gallons go to water changes between my DT and QT tanks. I have a 100gpd system.

That's very interesting info, thanks!

I know it's highly dependent on each person, but I'm only running a 55 Gallon DT and a 20 Gallon QT which is of course temporary. 70 ppm TSD tap water, 4 ppm out of membrane. Sounds similar to your numbers but with a smaller setup (also a 100gpd system).

In that case, could I assume that I would PROBABLY be able to expect similar results? Then again, I don't have 2 Carbon or a DI on my system, so maybe that makes that much of a difference? That said, if a DI would last that long for me as well, that would at least be more worth it in my mind, but if I have to change Sediment, Carbon, and DI every 3-6 months, that's getting a bit heavy on the Wallet ha.

What system are you using? Maybe that makes a difference?

Also, $10 in filters? Where are you getting 1 sediment and 2 carbons for $10!? Or did I read wrong? haha

 

[JSkeleton]

I change my sediment and carbon filters out annually. I change my DI resin when the color changes for all the resin in the container and my TDS output starts reading higher than zero.

Gotcha! What's your DT setup though (how many Gallons)? Are you producing a good amount weekly/monthly of RO/DI water?

I was under the assumption carbon had to be changed every 3 months because it inactivated after 3 months? And was also under the assumption that sediment would probably need to be changed every 6 months as well.

Also, have you noticed a typical time frame for your DIs to be changed?

 

[MONTANTK]

Yeah I don't have a DI, but I'm hearing some people say 4ppm isn't so bad? I know 0 is ideal, but man to have to throw in a DI too now and replace those every few months, at this point I'm ready to bow out and go back to freshwater as it's getting more and more expensive to maintain.

I mean it all depends on what your goal is with the tank. Would I leave saltwater over 4ppm? Probably not. You shouldn’t have any serious issues as long as you maintain the tank. Maybe consider just throwing a poly pad in the sump or something and down the road if you feel the need you can pick up a DI filter

 

[Jeffcb]

I only just got a TDS meter after making about 150-200 Gallons of RO Water with the “Aquatic Life RO Buddie Three Stage Reverse Osmosis, 100-Gallon”.

My tap water is reading 70ppm on the TDS and my RO is reading 4ppm. I know 0 is ideal, but does 4 mean I’ve burnt through the filters already? How do I know when to change them? I was expecting every 6 months but now I don’t know?

It is worth noting that I was reading from my BRUTE reservoir (never put salt in it) if that matters.

My TDS Meter is:

HM DIGITAL TDS-3 Handheld TDS Meter Tester​

Don't measure TDS in the Brute can.

What is it straight out of the R/O unit? Use a small clean glass.

 

[Koh23]

0 tds is 0 tds, really dont matter where u measure it.

If 0 tds is on ro out, then 0 tds needs to be in no matter what bucket, bin or can u put that water.

If it isnt, then something is leaching into water, dirty bucket, salt residue, etc.....