Does everyone just end up buying an RODI system eventually??

[LeftyReefer]

If I understand correctly, the BRS units that run at 1:1.5 (RO water to waste water) use two membranes, correct? Are they in series? Are these likely to need replacement more often in this configuration?

I'd like a unit that produces less waste water like the BRS unit, but not at the expense of having to replace the membranes more often.

I'm in the market for a new RODI too, so I'm following this one.

 

[Philly Reefer]

If I understand correctly, the BRS units that run at 1:1.5 (RO water to waste water) use two membranes, correct? Are they in series? Are these likely to need replacement more often in this configuration?

I'd like a unit that produces less waste water like the BRS unit, but not at the expense of having to replace the membranes more often.

I'm in the market for a new RODI too, so I'm following this one.

Yes they are in series. I don't know the answer regarding if it need to be replace more often or not.

It is a question that how long will the 2nd membrane last, will it be more expensive to replace the 2nd membrane vs the water bill?

Maybe @Bulk Reef Supply can chime in on this one

 

[MJ in Boise]

Water temp to membranes has a big effect on production. Nobody seems to touch on the subject. Anyone heat or cool the feed line to get closer to 77?

 

[K7BMG]

Water temp to membranes has a big effect on production. Nobody seems to touch on the subject. Anyone heat or cool the feed line to get closer to 77?

I agree but I don't know many situations where temprature will be a factor.
I would say few if any would use them in a close to freezing envirnment.
More in hotter environments.

 

[K7BMG]

Any way this thread is now Deviating from the OP's initial question.
To buy and implement a RO/DI unit.

The other topics should be taken to another thread.

Many of these topics have been well covered already and a search will take you there for further discussion.

 

[92Miata]

RODI units very quickly pay for themselves (because LFS/store/etc water is expensive) in water alone - and that doesn't get into *knowing* that you're using good water vs trusting someone else is doing their maintenance.

Its one of the better expenditures you can make.

 

[Buckeye Hydro Verified Sponsor]

so in conclusion, it will deteriorate the 2nd membrane faster? (as mentioned by @burnetb1 )
Is there other negative side effect beside that?
I can only tell you in my own set up /experience that it worked to produce more RODI water and less waste water.

Higher RO water TDS. Will it produce less concentrate? Sure. Of course. Until the membranes load with scale. If that's all you want to do, simply place a tighter flow restrictor on a single membrane and you'll accomplish the same thing.

 

[Fishko]

Lol it was literally the first thing i bought

 

[Brew12]

Ok guys,
So I thought I could make it work for aquarium water with my filtration system I have now that I use for my drinking water but I don't think its going to be good enough to do my own water changes with it. I have tried but my parameters still aren't coming out exactly perfect. My LFS told me it would be fine but I still can seem to get my pH and others at zero. Does everyone just get their own RODI system eventually if they have a larger tank?? Bc trips every week or so to fish store with my big buckets seems like it's gonna get old pretty fast lol and is buying used an option?? Trying to find one that would be a good fit for my 70 gal.

I'm going to go against the grain on this one. I would call your local water utility and find out if they add chloramine to your water. Getting a water report would be good, too. I suspect that your drinking water filters will be just fine as long as you intend to do regular water changes.

I consider RODI to be absolutely mandatory if you want to minimize water changes. Some impurities will build up over time that may not be a problem initially but becomes a problem as it is concentrated by evaporation.

Otherwise, RODI may or may not be required depending on the quality of your tap water. It is nice for some peace of mind that your water can be eliminated as a cause of concern. My city water is very good, but I make my own RODI anyway. I wouldn't lose any sleep over it if I had to use tap water to make salt water in an emergency.

 

[lefkonj]

You can definitely drink water out of a RODI system. Why couldn’t you? It’s just water.

It was my understanding that since RODI is completely stripped of all its minerals, as well as impurities, it is not a good source for humans. I was under the impression that home water filters don't do the DI piece. I could be wrong though.

 

[Dr. Dendrostein]

These no waste ro filtration systems, you do have to add DI resin and I added two canisters DI resin and I get 0 TDS

 

[ichthyoid]

Ok guys,
So I thought I could make it work for aquarium water with my filtration system I have now that I use for my drinking water but I don't think its going to be good enough to do my own water changes with it. I have tried but my parameters still aren't coming out exactly perfect. My LFS told me it would be fine but I still can seem to get my pH and others at zero. Does everyone just get their own RODI system eventually if they have a larger tank?? Bc trips every week or so to fish store with my big buckets seems like it's gonna get old pretty fast lol and is buying used an option?? Trying to find one that would be a good fit for my 70 gal.

Unless your water supply has low total dissolved solids, you may. This applies to much/most of the US.

Those of us that have naturally soft water may be able to get by without an RO membrane & benefit from higher throughputs as well.

My local TDS is around 40 mg/liter. It’s worth a check of your local water source, before spending the extra money of a full RO/DI system, imo.

 

[Brew12]

These no waste ro filtration systems, you do have to add DI resin and I added two canisters DI resin and I get 0 TDS

That likely makes sense for a drinking water system, but if I were looking for a RODI system for my aquarium I wouldn't use it. You have no way to remove the non ionic minerals from the water.

 

[JoshH]

These no waste ro filtration systems, you do have to add DI resin and I added two canisters DI resin and I get 0 TDS

This is not an RO system atall. It also does not reduce TDS even remotely as much as an RO system does. From the bottom portion of that page....

It is essentially a fancy carbon filter and membrane that maintains TDS at or below 500 in there "Ideal range" of 300-500....

 

[Philly Reefer]

Higher RO water TDS. Will it produce less concentrate? Sure. Of course. Until the membranes load with scale. If that's all you want to do, simply place a tighter flow restrictor on a single membrane and you'll accomplish the same thing.

Then why don't all rodi system use tighter flow restrictors in the 1st place? I would think there must be a reason why the current flow restrictor is in place?

 

[dbowman5]

Terrible well water keeps me from making rodi. I still make RO to drink. LFS here doesn't charge for RODI, so I make 60gal water runs and run it through a sediment then mixed bed DI to ensure purity. Their water always tests at 0 but better safe than sorry. If you have the ability to make your own do it.

i have looked into CO2 issues with ground water. i wonder if ground water to holding tank (allow circulation turbulence to off gas the CO2) after some dwell time in the holding tank, pumped through a RODI would eliminate the premature aging of the DI resin this is discussed on this site.

 

[Dr. Dendrostein]

This is not an RO system atall. It also does not reduce TDS even remotely as much as an RO system does. From the bottom portion of that page....

It is essentially a fancy carbon filter and membrane that maintains TDS at or below 500 in there "Ideal range" of 300-500....

When I bought it four months ago or less , it didn't have that disclaimer at the bottom. Now it does, that's why I mentioned I add DI resin I get zero TDS

 

[KStatefan]

Then why don't all rodi system use tighter flow restrictors in the 1st place? I would think there must be a reason why the current flow restrictor is in place?

Because the membrane will not last like it was designed but that comes at the cost of more water usage to run it. If getting the least amount of waste water is your main concern restrict the waste line more.

 

[MJ in Boise]

i have looked into CO2 issues with ground water. i wonder if ground water to holding tank (allow circulation turbulence to off gas the CO2) after some dwell time in the holding tank, pumped through a RODI would eliminate the premature aging of the DI resin this is discussed on this site.

People do it and it works. I just dont have the space for an 8th brute in the garage. Takes about a day and a ton of aeration to kick it out.

 

[JoshH]

When I bought it four months ago or less , it didn't have that disclaimer at the bottom. Now it does, that's why I mentioned I add DI resin I get zero TDS

I'd still be concerned you might be burning through resin much quicker than you normally would be, have you checked your TDS after the membrane before your DI atall? Maybe you have rather low TDS to begin with and this particular system works well enough. The cost of water is pennies compared to the cost of DI resin. So I'd hate to see it cost you more in the long run