What is an acceptable TDS reading??

[spoonman]

I bought my RO/DI unit about 3 months ago. I just got a TDS meter last week. My TDS readings out of my unit are 024ppm. Is this acceptable? At what point do you replace the cartridges? My tap water is 394 if that makes a difference.

 

[AquaRick]

Not sure what "acceptable" readings are; but my output rodi water always reads 0.

 

[carey]

I also have 0 tds water out of my unit. How much water are you making? lol maybe you blew through the filters already...

 

[AquaRick]

Did some research, 394 tds out of your tap is pretty high. Checked my tap and it's at 12. Like Carey said, maybe you did go though your filters already?

 

[FTMMWS]

That is high for tap ,but obviously considered safe..I think 500 is the limit for drinking/using..
We are very fortunate to only have a TDS reading of 35-40...I don't even use an RO/DI water/unit..We do have a whole house Culligan system that removes heavy metals and the chlorine.. Not TDS though
I do not have full reefs but the shrooms and rics i have do just fine,,but they'd grow in much worse conditions i'm sure

 

[cmor1701d]

So a RO membrane is between 90% (100 gpd) and 99% effective for rejection rates. At 394 out of the tap, 24 ppm is ok for RO. If you also have a DI filter then the output should be 0 - 3.

My tap runs between 185 and 230 on the tds meter. I have a 150 gpd membrane rated at 99% and my RO water normally tests at 0 - 2. Anytime I see >0 after the DI I replace the DI resin.

First recheck the way you have it set up. If your unit is only 3 months old you should check with the place you bought it from.

One other thought, do you know anyone else with a RODI unit? Check your meter against their unit and their meter against your unit to make sure the meter is not the problem.
How many stages do you have, and do you have a DI filter?

I'll repeat the recommended cartridge ratings for a 5 stage unit.
10 micron Sediment filter
5 micron Charcoal
1 micron Charcoal
RO Membrane
DI resin

That way you are feeding the RO membrane water that has no particles greater than 1 micron and you are not clogging the filter at the first stage.

 

[spoonman]

I also have 0 tds water out of my unit. How much water are you making? lol maybe you blew through the filters already...

I have probably made less than 500 gallons through my unit. I have the pure water club 50gpd unit. And it is RO/DI. I am wondering if the unit is just sub-par.

 

[spoonman]

I will buy a gallon of distilled and check my TDS meter. Should be 0 right?

 

[MDChurch]

I too am running a unit from pure water club. The 150gpd unit. My tap water reads 170-190 and after RO/DI my readings are 0. I have been running the unit about 4 or 5 months now. I usually make about 40gal. of RO twice a week. I use an inline tds meter and flush the system before and after every use. Seems to be working great always have a tds of 0

 

[AquaRick]

Yes, distilled should be 0.

 

[carey]

I also have had the 150gpd purewater club unit and never had any issues with it. I started getting a tds reading of about 2 -3 after about 6-8 months of heavy use and replaced the 3 filters and tds went back to 0. Out of my tap the tds is about 250.

 

[spoonman]

I have been having some algae issues in my 29 gallon recently. I wonder if 024 would be enough to cause that?

 

[mr_X]

It would be. You don't need a new unit though. Maybe new D.I. resin.

 

[spoonman]

New di canister from pure water club is $15. Guess I will order one.

 

[Rutrag]

New di canister from pure water club is $15. Guess I will order one.

I'm not sure if Pure Water Club has one or not, but I would invest ina refillable DI canister. I know Bulk Reef Supply makes one that comes with the media. I think it was about $35. It will hold more of the DI resin and I think will produce pure water for a longer time and end up saving you cash since you'll only need the resin itself in the future.

 

[carey]

Purewater club has both the refillable canisters and the non. The clear canisters are usually the refillable ones. I think I paid $12 for a non refillable and $15 for a refillable one with the DI included of course. lol

 

[spoonman]

@carey, what do you like about your BRS ro/di unit that you didnt like about the PWC one? I am thinking about getting one in the next BRS group buy. I like the idea of the clear canisters so that you can tell the status of the canisters.

 

[carey]

I like that the filters are industry standard so you can get them anywhere, not just from one source. Also like the bells and whistles, the dual tds meter, the pressure gauge and the flush kit too. Overall the BRS unit is solid and sturdy, you can't go wrong if you get one. The PWC one was great while I had it, always produced clean water for me and I liked the portable aspect of it. The BRS unit is now mounted on the wall on my patio, it's quite large.

 

[Flreefer]

Carey, how much did that unit cost? And what does it cost you to maintain it? Ie new filters, etc.

 

[carey]

During the group buys the "Plus" unit is only $180 so I got that one. Comes with everything you could need. The sediment filters I believe are like $5 and the carbons are about $12 or so. You can get a refill of DI resin for I think $20 or so from BRS as well.

They also have a unit for I think $120 or so that doesn';t have the tds meters or the pressure gauge. Its the same unit without the bells and whistles pretty much. You can also go into the ro/di section on the BRS site and "make your own". That way you can pick and choose exactly what you want.